A fairly random collection of links on Merkle Trees

Just sitting around, hanging out, musing about Merkle Trees...

• Merkle tree

  Hash trees can be used to verify any kind of data stored, handled and transferred in and between computers. Currently the main use of hash trees is to make sure that data blocks received from other peers in a peer-to-peer network are received undamaged and unaltered, and even to check that the other peers do not lie and send fake blocks.

• A Certified Digital Signature

  The method is called tree authentication because the computation of H(1,n,Y) forms a binary tree of recursive calls. Authenticating a particular leaf Y(i) in the tree requires only those values of H() starting from the leaf and progressing to the root, i.e., from H(i,i,Y) to H(1,n,Y).

• Recent Improvements in the Efficient Use of Merkle Trees: Additional Options for the Long Term

  Fractal Merkle Tree Representation and Traversal, shows how to modify Merkle’s scheduling algorithm to achieve a space-time trade-off. This paper was presented at the Cryptographer’s Track, RSA Conference 2003 (May 2003). This construction roughly speeds up the signing operation inherent in Merkle’s algorithm by an arbitrary factor of T, (less than H), at a cost of requiring more space: (2^T times the space).

• Merkle Signature Schemes, Merkle Trees and Their Cryptanalysis

  The big advantage of the Merkle Signature Scheme is, that the security does not rely on the difficulty of any mathematic problem. The security of the Merkle Signature Scheme depends on the availability of a secure hash function and a secure one-time digital signature. Even if a one-time signature or a hash function becomes insecure, it can be easily exchanged. This makes it very likely that the Merkle Signature Scheme stays secure even if the conventional signature schemes become insecure.

• Caches and Merkle Trees for Efficient Memory Authentication

  Our work addresses the issues in implementing hash tree machinery in hardware and integrating this machinery with an on-chip cache to reduce the log N memory bandwidth overhead.

• Protocol specification

  Merkle trees are binary trees of hashes. Merkle trees in bitcoin use a double SHA-256, the SHA-256 hash of the SHA-256 hash of something.

  If, when forming a row in the tree (other than the root of the tree), it would have an odd number of elements, the final double-hash is duplicated to ensure that the row has an even number of hashes.

  First form the bottom row of the tree with the ordered double-SHA-256 hashes of the byte streams of the transactions in the block.

  Then the row above it consists of half that number of hashes. Each entry is the double-SHA-256 of the 64-byte concatenation of the corresponding two hashes below it in the tree.

  This procedure repeats recursively until we reach a row consisting of just a single double-hash. This is the Merkle root of the tree.

• Amazon's Dynamo

  Merkle trees help in reducing the amount of data that needs to be transferred while checking for inconsistencies among replicas. For instance, if the hash values of the root of two trees are equal, then the values of the leaf nodes in the tree are equal and the nodes require no synchronization. If not, it implies that the values of some replicas are different. In such cases, the nodes may exchange the hash values of children and the process continues until it reaches the leaves of the trees, at which point the hosts can identify the keys that are “out of sync”. Merkle trees minimize the amount of data that needs to be transferred for synchronization and reduce the number of disk reads performed during the anti-entropy process.

• Cassandra: Using Merkle trees to detect inconsistencies in data

  A repair coordinator node requests Merkle tree from each replica for a specific token range to compare them. Each replica builds a Merkle tree by scanning the data stored locally in the requested token range. The repair coordinator node compares the Merkle trees and finds all the sub token ranges that differ between the replicas and repairs data in those ranges.

• The Dangers of Rebasing A Branch

  Personally, having studied Merkle Trees and discussed a possible use-case for using git/Merkle Trees as a caching solution, I view git as a entirely immutable structure of your code. Rebases break this immutability of commits.

• Sigh. "grow-only", "rebase is dangerous", "detached head state is dangerous". STOP. Stop it now.

  git is a bag of commits organized into a tree (a tree of Merkle hash chains). Branches and tags are symbolic names for these. Think of it this way and there's no danger.

  ...

  I didn't need a local branch crutch to find my way around because I know the model: a tree of commits.

  Understanding the model is the key.

  There are other VCSes that also use Merkle hash trees. Internally they have the power that git has.

• Google's end-to-end key distribution proposal

  Smells like a mixed blockchain/git type approach - which is a good thing. The "super-compressed" version of the log tip sounds like git revision hash. The append-only, globally distributed log is pretty much like a blockchain.

• Ticking time bomb

  Given only one verified hash in such a system, no part of the data, nor its history of mutation can be forged. "History" can mean which software runs on your computer (TPM), which transactions are valid (Bitcoin), or which commits have been done in a SCM (git, mercurial).

  So git is not magical, it is just a practical implementation of something that works. Any other *general* solution will be based on similar basic principles. Mercurial does this and there is a GPG extension for it.

Wow, that's a lot.

I shall have to find more time to read...

What I'm reading, Aurora ATC edition

Amazingly, some of our relatives in Illinois, even those living in Downers Grove, hadn't heard about the events in Aurora. I think it's one of those bizarre events that affected a handful of people very significantly, some of those people many thousands of miles away from the incident, but didn't affect others even one whit.

Anyway...

• FAA contractor charged with fire that halted Chicago flights

  "This is a nightmare scenario when we thought systems were in place to prevent it," said aviation analyst Joseph Schwieterman of DePaul University in Chicago. "Technology is advancing so fast that ... there's less of a need for air traffic control to be so geographically oriented. I think the FAA's going to find itself under a microscope."

• Everything you need to know about the Shellshock Bash bug

  The risk centres around the ability to arbitrarily define environment variables within a Bash shell which specify a function definition. The trouble begins when Bash continues to process shell commands after the function definition resulting in what we’d classify as a “code injection attack”.

• MySQL 5.7.5: GROUP BY respects functional dependencies!

  Most RDBMS-es implement the SQL92 behavior, and generate an error in case a non-aggregate expression appears in the SELECT-list but not the GROUP BY-clause. Because MySQL would not generate an error at all and instead would simply allow such queries while silently producing a non-deterministic result for such expressions, many users got bitten and frustrated.

• Scaling NoSQL databases: 5 tips for increasing performance

  Virtualization can be great. It provides the flexibility to use a single machine for multiple purposes, with reasonable security for non-critical business data. Unfortunately, it also influences memory access speed, which is critical for some NoSQL databases. Depending on the hypervisor and the underlying hardware capabilities, it can add 20-200% penalty in accessing memory for NoSQL workloads. I have witnessed this in testing, and it is also documented by a number of industry benchmarks. Newer generation hardware helps with better support for hardware assisted memory management unit (MMU), but there is still a significant impact for workloads that generate a lot of Translation Lookaside Buffer (TLB) misses (as NoSQL databases are wont to do).

• Why Scrum Should Basically Just Die In A Fire

  Of course, musing, considering, mulling things over, and coming to realizations all constitute a significant amount of the actual work in programming. It is impossible to track whether these realizations occur in the office or in the shower. Anecdotally, it's usually the shower. Story points, meanwhile, are completely made-up numbers designed to capture off-the-cuff estimates of relative difficulty. Developers are explicitly encouraged to think of story points as non-binding numbers, yet velocity turns those non-binding estimates into a number they can be held accountable for, and which managers often treat as a synonym for productivity. "Agile" software exists to track velocity, as if it were a meaningful metric, and to compare the relative velocity of different teams within the same organization.

  This is an actual thing which sober adults do, on purpose, for a living.

  "Velocity" is really too stupid to examine in much further detail, because it very obviously disregards this whole notion of "working software as a measure of progress" in favor of completely unreliable numbers based on almost nothing.

  ...

  Sacrificing "working software as a measure of progress" to meaningless numbers that your MBAs can track for no good reason is a pretty serious flaw in Scrum. It implies that Scrum's loyalty is not to the Agile Manifesto, nor to working software, nor high-quality software, nor even the success of the overall team or organization. Scrum's loyalty, at least as it pertains to this design decision, is to MBAs who want to point at numbers on a chart, whether those numbers mean anything or not.

• Relativistic hash tables, part 1: Algorithms

  One might wonder whether the resizing of hash tables is common enough to be worth optimizing. As it turns out, picking the correct size for a hash table is not easy; the kernel has many tables whose size is determined at system initialization time with a combination of heuristics and simple guesswork. But even if the initial guess is perfect, workloads can vary over time. A table that was optimally sized may, after a change, end up too small (and thus perform badly) or too big (wasting memory). Resizing the table would fix these problems, but, since that is hard to do without blocking access to the table, it tends not to happen. The longer-term performance gains are just not seen to be worth the short-term latency caused by shutting down access to the table while it is resized.

• How to Squeeze a Huge Ship Down a Tiny River

  Everything aligned on Monday, and the six captains set to work in the afternoon. Given the intense concentration needed to do the job, they worked in pairs for 90 minute shifts. One captain steered the bow, the other guided the stern. The unusual maneuvering system helps a ship this big precisely navigate tight turns and narrow squeezes, much like a tiller driver helps the driver of a hook-and-ladder firetruck navigate city streets.

  Spectators lining the river could be forgiven for thinking Quantum was headed upriver, given that it went downriver backward. Using the propellers to pull from the front offers better control than pushing from the back (the same is true for front wheel-drive cars). Tug boats, attached directly, rather than by a cable, to the bow and stern of the ship, provided extra control.

• File systems, Data Loss and ZFS

  ZFS is able to protect all of these things between the disks and system memory, with each change protected after an IO operation (e.g. a write) returns from the kernel. This protection is enabled by ZFS’ disk format, which places all data into a Merkle tree that stores 256-bit checksums and is changed atomically via a two-stage transaction commit. No other major filesystem provides such guarantees.

  However, that is not to say that ZFS cannot lose data.

• Another Patent Troll Slain. You Are Now Free To Rotate Your Smartphone.

  Rotatable owned a patent that it claimed covers the screen rotation technology that comes standard in just about every smartphone. You know, when you flip your device sideways and the screen shifts orientation from portrait mode to landscape mode? Like nearly all the apps in the Apple and Android app stores, Rackspace uses standard functionality provided by Apple’s libraries and Android open source software to provide this display feature in our mobile cloud applications.

• The Dropbox terabyte conundrum

  When you move items to Transporter Library, they are moved off of your device and into the Transporter’s personal cloud. You are offloading files from your system, for hosting elsewhere. Accessing them is slow, of course, because they’re not actually on your device. But they’re also not taking up space on that tiny solid-state drive of yours.

  It’s a clever approach, and one that I hope Dropbox adopts—but I’m a little concerned that Dropbox is so committed to its metaphor that it won’t want to complicate it like this. Allowing direct disk-like access to Dropbox is very different than syncing files, so it might require major changes to Dropbox’s infrastructure. I can see how it might not be a development priority.

• Liverpool beat Middlesbrough after 30-penalty Capital One Cup shoot-out

  It was the longest penalty shoot-out in the history of the League Cup, the previous record set at 9-8 on three occasions, and more extensive than the FA Cup’s highest total when Macclesfield beat Forest Green 11-10 in 2001. Of major English competitions only the Football League Trophy can equal it, also boasting a 14-13 shoot-out.

In other news, I made Hacker News!

For an essay I wrote last January.

But it was cool nonetheless.

And thanks, Kale, for including me in your newsletter!

Well, that was a bust.

Surely we weren't the only people affected by today's air traffic control snafu.

Our 6 day trip to Michigan won't happen, sadly; we declined the suggestion that we fly to "Baltimore or maybe Saint Louis, and then drive from there."

Instead, we'll plan another trip, perhaps this winter (we're already planning to go for Thanksgiving, too.)

The world can throw you a curveball, you just have to deal with it.

Rain! Actual rain!

OK, it was only for a few hours.

But it was actual rain!

Wow that felt good.

What I'm reading, autumnal equinox edition

Confucius says: he who attends all-week company conference while battling nasty head cold sleeps 10 hours / night over next weekend.

At any rate, I'm feeling somewhat better now, and am back to surfing the nets.

• Guide: Writing Testable Code

  To keep our code at Google in the best possible shape we provided our software engineers with these constant reminders. Now, we are happy to share them with the world.

• Why DO Computers Fail?

  The obvious question when reading a text this old is just how relevant the information is for the world of computing today. I see no reason to think that the fundamental principles have changed, even though all numbers in the report are way off compared to current technology. For example, in a description of a restart scenario, he cites a time of about 90 minutes from start to a live system. Today, most systems would come up much faster than that. The nature of networking has changed dramatically from 1985 in terms of speed and latencies and robustness. Even so, it is still true that communications links are normally the weakest link in any distributed system.

• High Performance SSH/SCP - HPN-SSH

  SCP and the underlying SSH2 protocol implementation in OpenSSH is network performance limited by statically defined internal flow control buffers. These buffers often end up acting as a bottleneck for network throughput of SCP, especially on long and high bandwith network links. Modifying the ssh code to allow the buffers to be defined at run time eliminates this bottleneck. We have created a patch that will remove the bottlenecks in OpenSSH and is fully interoperable with other servers and clients. In addition HPN clients will be able to download faster from non HPN servers, and HPN servers will be able to receive uploads faster from non HPN clients. However, the host receiving the data must have a properly tuned TCP/IP stack. Please refer to this tuning page for more information.

• Memory Management Reference

  This is a resource for programmers and computer scientists interested in memory management and garbage collection.

• Resource management in Docker

  Docker uses cgroups to group processes running in the container. This allows you to manage the resources of a group of processes, which is very valuable, as you can imagine.

• What is linux-gate.so.1?

  From time to time this is a cause of befuddlement and frustration for users as they go searching for a non-existent system file. You can confidently tell users on this futile quest that there's not supposed to be a linux-gate.so.1 file present anywhere on the file system; it's a virtual DSO, a shared object exposed by the kernel at a fixed address in every process' memory

• I’m leaving Mojang

  I was at home with a bad cold a couple of weeks ago when the internet exploded with hate against me over some kind of EULA situation that I had nothing to do with. I was confused. I didn’t understand. I tweeted this in frustration. Later on, I watched the This is Phil Fish video on YouTube and started to realize I didn’t have the connection to my fans I thought I had. I’ve become a symbol. I don’t want to be a symbol, responsible for something huge that I don’t understand, that I don’t want to work on, that keeps coming back to me. I’m not an entrepreneur. I’m not a CEO. I’m a nerdy computer programmer who likes to have opinions on Twitter.

• Why Free Marketeers Want To Regulate the Internet

  it seems odd for a conservative – whether an old-guard big-business Bush-era conservative or a new-guard Paulite libertarian conservative – to support Net Neutrality.

  Except I do Internet for a living, and I am one of the lucky ones who actually knows what Net Neutrality means and what it’s responding to. And, folks, I’m afraid that, while L. Gordon Crovitz and Rich Lowry are great pundits with a clear understanding of how Washington and the economy work, they don’t seem to understand how the Internet works, which has led them to some wrong conclusions.

• Eleventh Grade Tech Trends

  So while the anecdotes of a sixteen year old, public high school student, from Los Angeles are not representative, and will not help you find the next Facebook, I do think the practice of pausing, asking questions, and listening to other people is a good one that should be practiced much more.

• How Gangs Took Over Prisons

  This past summer, however, a 32-year-old academic named David Skarbek published The Social Order of the Underworld, his first book, which is the best attempt in a long while to explain the intricate organizational systems that make the gangs so formidable. His focus is the California prison system, which houses the second-largest inmate population in the country

• Here Comes Habitat

  The MADE, a few months ago, quietly began working on reviving the game Habitat for preservation. The period we have thus far completed has mostly been focused on gathering human resources, hardware resources, and assessing the extent to which we can preserve the first Massively Multiplayer game. At this point, we are ready to announce that we feel we have a very good chance of bringing Habitat online, in its original form, for play online with Commodore 64 emulators as the client.

• iOS 8, thoroughly reviewed

  In this review, we'll be talking mostly about features available to all iOS 8 devices, and to hardware that you already have in your hands right now. Several software features in the new operating system are exclusive to the new iPhone 6 and iPhone 6 Plus, and discussion of those features will wait until we review those devices.

• What every computer programmer should know about floating point, part 1

  There is an existing article called What Every Computer Scientist Should Know About Floating-Point Arithmetic, but it is very math-heavy and focuses on subtle issues that face data scientists and CPU designers. This article ("What every computer programmer should know...) is aimed at the general population of programmers. I'm focusing on simple and practical results that you can use to build your intuition for how to think about floating-point numbers.

• Dread Pirate Sunk By Leaky CAPTCHA

  The IP address leak we discovered came from the Silk Road user login interface. Upon examining the individual packets of data being sent back from the website, we noticed that the headers of some of the packets reflected a certain IP address not associated with any known Tor node as the source of the packets. This IP address (the “Subject IP Address”) was the only non-Tor source IP address reflected in the traffic we examined

• NOAA team reveals forgotten ghost ships off Golden Gate

  A team of NOAA researchers today confirmed the discovery just outside San Francisco’s Golden Gate strait of the 1910 shipwreck SS Selja and an unidentified early steam tugboat wreck tagged the “mystery wreck.” The researchers also located the 1863 wreck of the clipper ship Noonday, currently obscured by mud and silt on the ocean floor.

  These and other shipwreck investigations mark the first mission of a two-year project to locate, identify and better understand some of the estimated 300 wrecks in Gulf of the Farallones National Marine Sanctuary, and the adjacent Golden Gate National Recreation Area.

Oh, and yes, the rumors are true: I now use an iPhone.

MRAP-a-tat-tat

What.

Just what.

The world is insane.

• Bay Area police departments got millions in military surplus, records show

  Asked why Antioch police needed a mine-resistant personnel carrier weighing more than 30,000 pounds, Antioch police Captain Leonard Orman said the vehicle was critical to the department's ability to protect officers during a natural disaster or in incidents that require a SWAT team.

  "It's a defensive vehicle that provides the ability to be protected from gunfire, including high-powered rifles," Orman said. "If someone is barricaded in a home and there is an injured person on the ground, we can use it to rescue the person without exposing ourselves to fire."

  ...

  UC Berkeley's police department used the 1033 program to request about a dozen M-16 rifles, which it said would give officers firepower equal to that held by some of the criminals they encounter, said Lt. Eric Tejada, a department spokesman.

  "We feel that those specialists need to have a rifle that's capable of dealing with some incidents that can involve the modern-day weapons that you see now," Tejada said. "It's smart for us to utilize the resources that you can get for free."

• Davis acquires mine-resistant war vehicle while some complain of militarization of police

  Chief Landy Black of the Davis police defended the acquisition of the MRAP, saying in a statement that its heavy armor “makes it the perfect platform to perform rescues of victims and potential victims during … active-shooter incidents, and to more safely deliver officers into an active-shooter incident.”

  ...

  “I can’t imagine why Davis needs a tank,” Davis Mayor Dan Wolk said Wednesday. “It’s in a city garage and I hope it stays there.”

• Dozens of police departments suspended for losing US military-grade weaponry

  According to the media outlet Fusion, its independent investigation into the Pentagon’s “1033 program,” which equips state and local police departments across the US with excess military equipment, turned up an alarming trend: Not only did many law enforcement agencies fail to comply with the program’s guidelines, they routinely lost dangerous weaponry.

  Already, the investigation has found that police departments in Arizona, California, Mississippi, Missouri, Georgia, and others have lost or cannot account for various types of weapons. This list includes M14 and M16 assault rifles, .45-caliber pistols, shotguns, and even vehicles.

• The Pentagon Is Giving Grenade Launchers To Campus Police

  David Perry, the president of the International Association of Campus Law Enforcement Administrators, told Politico that 1033 mostly funnels “small items” to college police forces for daily use. These could be anything from office supplies or uniforms or car parts, but it’s probably not all that tame. Campus Safety magazine recommends that universities take part in the 1033 program to cover a range of needs from storage units to grenade launchers. That is, after all, what the program was designed to achieve.

• Finding Funds for Your Equipment, Programs and People (Part 2 of 2)

  Military surplus and contractors via the 1033 program, however, can be excellent sources of used equipment.

  The 1033 program (formerly the 1208 program) permits the secretary of defense to transfer excess U.S. Department of Defense personal property (supplies and equipment) to state and local law enforcement agencies. Anything from used grenade launchers (for the deployment of less lethal weapons) to trucks to boats to storage units may be available for a significantly reduced cost.

• Ferguson aftermath: California city tells cops to get rid of armored vehicle

  Davis Police Chief Landry Black made the case for keeping the MRAP, saying the police department had confiscated much high-power weaponry in the last year. He said there were specific guidelines for its use, and that it is a necessary piece of safety equipment for the city.

• Police Armored Vehicle Is Unwelcome in California College Town

  Sheriff Brown of Santa Barbara County said there had been “a lot of misunderstanding about the program — in some quarters, even hysteria.”

  “The reality is that this is a great program,” he said. “It provides law enforcement with a lot of very valuable equipment that in many instances — in fact, most instances — could not be obtained or afforded, and allows us to do a better job of protecting our citizens and our own public safety personnel.”

• Commentary: A militarized police force may see its citizens as the ‘enemy’

  Even college security forces are getting their share: A sidebar noted that nine out of 10 universities employ armed officers authorized to use deadly force.

  And in 2013, “the campus police at The Ohio State University procured a Mine-Resistant Ambush-Protected vehicle (MRAP), according to the Daily Caller website. The vehicle, which school officials noted was ‘acquired at no cost from military surplus,’ has a gun turret on the roof and is designed to stave off ambushes and roll over improvised explosive devices. OSU was also the first agency in the state to acquire an MRAP at the time.

"Campus Safety Magazine"? There is such a thing?

My head hurts. I am sad.

Trinity: a very short review

Leon Uris's Trinity is generally considered to be one of the author's best works. For thematic reasons, it was one of my vacation readings.

Trinity is 900 pages long. The first 600 pages are superb, and just flew by. This is the portion of the book which covers the period, roughly, from the Great Famine through the Industrial Revolution, say, late 1830's through late 1880's. The characters were compelling, the storytelling was both exciting and colorful, and the book managed to be somehow intimate and sweepingly epic at once.

The genius of this part of this book is the way that Uris helps you understand why people behave the way they do, not by explaining it to you, but by showing you how it happens. People don't just wake up one day and do something dreadful to each other, it happens over a period of time, through untold zillions of tiny step by step actions and individual decisions, each of which seems simple and obvious and inevitable but they all add up.

The last 300 pages, covering roughly the first quarter of the 20th century, just didn't work for me.

A slimy subject

One of the things we noticed on our trip to Ireland was that, every time we explored the actual coastline (beaches, rocky cliffs, fishing piers, etc.), there were a surprising number of jellyfish.

I mean, a really surprising number.

Somebody mentioned that maybe this was actually a known and studied phenomenon, so I went searching.

Anyway, once you start reading this article in The New York Review Of Books you won't stop thinking about it: They’re Taking Over! .

Our changing climate is also having many impacts on jellyfish. As the oceans warm, the tropical box jellyfish and the Irukandjis are likely to extend their ranges, while other species will benefit from the lowered oxygen levels that warmer waters contain. Remarkably, jellyfish may have the capacity to accelerate climate change. This can happen in two ways. Jellyfish release carbon-rich feces and mucus (poo and goo) that bacteria prefer to use for respiration. As Gershwin puts it, “jellyfish blooms turn these bacteria into carbon dioxide factories.” But jellyfish also consume vast numbers of copepods and other plankton. These creatures migrate vertically through the water column, taking in carbon-rich food at the surface and releasing it as fecal pellets, which fall to the sea floor and are buried. The plankton are thus a major means of taking carbon dioxide out of the atmosphere and oceans. If their loss occurs on a large enough scale, it will hasten climate change.

Perhaps we will soon be seeing bumper stickers: "Save the plankton, eat a jellyfish!"

What if? A very short review

As everyone knows, I am one of the biggest Randall Munroe superfans on the planet.

Thus my expectations for What If?: Serious Scientific Answers to Absurd Hypothetical Questions were sky-high.

I am not disappointed!

California's climate casualties

Yowza, it's getting ugly:

• The stupendous man-made reservoirs of far Northern California are now essentially empty, something that's never happened since I've lived here: Dramatic Photos of California's Historic Drought
• And the fall fire season is upon us, with a vengeance: Yosemite fire near Half Dome forces airlifting of 85 people

When I was up high, high, high in the Sierra Nevada mountains at the end of July, one thing was clear: there is no water in the mountains.

Something's gotta give, and it's gotta start happening soon.

Where are our politicians? Our civic leaders? Our community/religious/commercial leaders?

Hello? Shouldn't we all be talking about this?

Donald MacKenzie on High Frequency Trading

A bit of my weekend reading was this nice short piece by Donald MacKenzie in the London Review of Books: Be grateful for drizzle.

MacKenzie takes a level-headed and clear-eyed look at the phenomenon of High Frequency Trading as it stands in the summer of 2014.

One interesting topic that he covers involves the difference between programs which play the role of market-makers, and programs which play the role of traders.

Market-makers are beasts of burden in the market: their job is to match up interested buyers with interested sellers, charging a price for this service made up of the spread between the purchase price and the sale price and the rebate awarded them by the host exchange:

If a market-making program is trading Apple shares, for example, it will continually post competitively priced bids to buy Apple shares and offers to sell them at a marginally higher price. The goal of market-making is to earn ‘the spread’, in other words the difference between those two prices – in Apple’s case, a few cents; in many other cases, a single cent – together with the small payments (around 0.3 cents per share traded) known as ‘rebates’ that exchanges make to those who post orders that other traders execute against.

Adam Smith's "invisible hand" works well here: if the market-maker's spread is too large, others will offer a lower spread and will take business away from the weaker program; this competition drives the market-making programs to be efficient and to offer the smallest possible spread, which benefits all participants in the market.

Traders, on the other hand, are opportunists, attempting either to buy low and sell high, or to sell high and buy low; in either case, the trading program attempts to identify the direction that a stock price is moving and front-run it. These traders don't really care whether the stock prices is moving up or down; they just care whether they can reliably detect that movement before any other trader can, thus being able to profit from it:

you have to pay the exchange a fee, rather than earning a rebate, and, if prices don’t move, your program can end up simply ‘paying the spread’ to market-making programs, because it will have to sell more cheaply than it buys. However, if an HFT program can identify a trading opportunity larger than the ‘spread’ (a high probability that, for example, the price of the shares being traded is going to rise or fall by several cents), then it may well need to act immediately and aggressively, before other programs do.

Trading programs don't benefit any market participants other than themselves, which is why they've earned considerable ire.

However, it's not clear that they are intrinsically evil; they are just feeding off of inefficiencies elsewhere in the system. MacKenzie discusses, in detail, one such inefficiency, told in Michael Lewes's Flash Boys, involving the way in which a large bank decides to execute an extremely large order for one of its pension fund customers; the bank's poor handling of the order results in a tidy opportunity for these aggressive trading programs.

And as MacKenzie notes, behind all these high-tech maneuvers are the hard-earned savings of ordinary people like you and me:

Behind orders from banks’ institutional investor customers are people’s savings and pension funds. Flash Boys has been widely read as a morality play, a story of evil-doing high-frequency traders. But it can just as easily be read as an account of banks that either wouldn’t, or didn’t know how to, take best care of their own or their customers’ orders. To their credit, the Royal Bank of Canada team took action once they saw the disadvantage they were labouring under. I am assured by a source that other banks have done things to reduce the problem, for example moving their smart order routers from Manhattan into the data centres in New Jersey. All things considered, I suspect that what drains most money from pension funds and other savings are the high fees charged by those who manage them, and the excessive trading they often engage in, not high-frequency trading or even the incompetent handling of orders.

Over the years, as I've learned, in bits and pieces and dribs and drabs, about the activity of High Frequency Trading, I've come to roughly the same conclusion as MacKenzie appears to have arrived at:

• Automated market-making is not only not evil, it's actually been quite beneficial. Spreads have dropped, liquidity is generally quite high, individual investors like myself have access to very open and fair markets, and computers are actually very good, and very very efficient, at doing the automated market-making and book-keeping necessary for all this to occur.
• Aggressive traders, who think they can predict market movements, or at least detect and respond to them faster than others do, can be quite annoying, but there's really no evidence that they are a problem worth wasting much energy over.
• Poor oversight, transparency, and regulation of retirement funds, on the other hand, is the source of much waste if not outright corruption.

When a bank's inefficient trading desk causes a large order submitted by a state government's public employee retirement fund to be mis-handled, resulting in a bad execution, no money is strictly speaking 'lost'; however, a certain amount of money is effectively transferred from the retirement fund to those trading programs which took advantage of that poor execution.

And that means that those trading firms took money from you and I, since in the end that public employee retirement fund is funded by the taxes that we pay that are used to pay the salaries of those policemen and firefighters and teachers and contribute to their retirement savings.

My personal bug-a-boo in this area involves 401K fund selection. Individual employees like myself are at the mercy of what is provided by my company's retirement plan, which in turn is at the mercy of what the "financial services" industry is willing to provide. And, naturally, most of that industry wants to provide high-fee, poorly-run funds which take my hard-earned savings and send a depressingly large amount of it to the plan servicing company's executives.

But as MacKenzie points out, it's important to keep your eye on the overall picture here:

The right question to ask about high-frequency trading is not just whether high-frequency traders are good or bad, or whether they add liquidity to the markets or increase volatility in them, but whether the entire financial system of which they are part is doing what we want it to do. Of course, we want it to do several things, but I’d say that high on the list should be putting people’s savings to the socially most productive uses, while preventing too much of those savings being wasted along the way.

Speaking a couple of years ago to Bloomberg Businessweek about the new, faster cables, such as those planned by Hibernia, Manoj Narang, founder of the HFT firm Tradeworx, commented: ‘Nobody’s making extra money because of them: they’re a net expense … All they’ve done is impose a gigantic tax on the industry and catalyse a new arms race.’ The chief economic characteristic of an arms race is that all the participants have to spend more money, and none of them ends up any better off because of it.

The world financial system is capable of great wonders, but also capable of great devastation (witness 2008, after all).

Somewhere in there is the possibility of a system whose power is harnessed, but whose threat is contained.

And the road to that hopeful future lies in the work of clear-thinking writers like MacKenzie, who take the time to study the details and understand them and explain them to people like me so we can think about them.

So if this is a topic that interests you, I recommend you read MacKenzie's article in full.

Fabiano Caruana at Sinquefield 2014

The chess world is abuzz with the extraordinary performance of Fabiano Caruana at this year's Sinquefield Cup:

• On Chess: St. Louis Witnessing Chess History-As-It-Happens At Sinquefield Cup

  The 2014 Sinquefield Cup, the global super-tournament now in progress in the Central West End, had already been prepared to leave its mark in time. Headlined by reigning World Chess Champion GM Magnus Carlsen, along with five other of the world’s top-10 International Grandmasters, the event was set to become a part of chess lore even before its first move: The six-player field is the strongest-rated ever, averaging a 2802 strength never seen in the game’s 1,500-year history.

• Caruana Demolishes Topalov, Increases Lead Again

  Caruana began his second time around the field, but so far it's looking the same as the first. A mere 31 moves and barely three hours was all it took to take out GM Veselin Topalov in round six.

• Grande! Mostruoso! Fabiano Caruana is at 7,0/7 at Sinquefield Cup

  Day after day the Italian-American superstar Fabiano Caruana is making history. Fabulos Fabiano aka Fabi is now at 7,0/7 in the strongest ever chess tournament, the Sinquefield Cup, breaking every expectation, shattering even the bravest predictions.

  With his victory in round 6 he surpassed the 5,0/5 start of Ivanchuk at Mtel Masters 08, with the victory today another achievement remains behind – the 6,0/6 of Karpov in Linares 1994. The modern times of chess have a new king, king Fabiano Caruana. One has to look back to 1968 where in Wijk Aan Zee the legendary Korchnoi started with 8,0/8. The times now are so different and the competition so fierce that already Fabiano’s success can be proclaimed as the most memorable streak in the history of chess.

• Sinquefield Cup Round 8: The Streak Ends, But Caruana Clinches Tournament Victory With Two Rounds To Spare

  In today's game he was close to a win against Carlsen, but 26. 0-0 let the foot off the gas and Carlsen scraped his way to a drawish ending, one which Caruana didn't seem too intent to try to win. From the perspective of tournament victory, a draw was sufficient, and for all his strength and ambition even Carlsen cannot hope to make up a three point deficit in the two remaining rounds.

• Undefeated Caruana Wins Sinquefield Cup by Three Points

  Fabiano Caruana finished the 2014 Sinquefield Cup with a solid draw against Levon Aronian to end the highest-rated tournament in history with a magnificent 8.5/10 -- three points ahead of his nearest follower, the World Champion GM Magnus Carlsen.

• Fabiano Caruana wins Sinquefield Cup with stunning performance

  There are only two historic precedents for such a runaway start in an elite event. Long ago at Avro 1938 Reuben Fine began with 5.5/6 against a sextet who included four world champions – José Capablanca, Alexander Alekhine, Max Euwe and Mikhail Botvinnik. And at Linares 1994 Anatoly Karpov began 6-0 before drawing in round seven with Garry Kasparov. Karpov finished with 11/13 in what was widely considered the best tournament performance of all time.

The Ireland Trip, chronologically arranged

Blogs tend to show information in reverse order, so if you're looking to read about our summer vacation in chronological order, here it all is, in one easy article:

• Two days in Central London: Day One
• Central London in Two Days: Day Two
• Ireland Day One: Arriving and Driving
• Ireland Day Two: Dingle
• Ireland Day Three: The Ring of Kerry
• Ireland Day Four: Killarney National Park
• Ireland: Sneem to Kinsale
• Ireland day six: South and West County Cork
• Ireland Interlude
• Ireland day seven: East County Cork
• Ireland day eight: the Rock of Cashel
• Ireland day nine: A bunch of Blarney
• Ireland day 10: wrapping up

Ireland day 10: wrapping up

Our last day in Ireland was chaotic, but fun. If I told you that we managed to have breakfast in Adare, Ireland, and dinner just a few blocks from Buckingham Palace, would you believe me?

Well, here's how it all went:

After a nice breakfast in Adare, I enjoyed the Adare Heritage Museum while Donna enjoyed the Adare craft stores (where we bought a beautiful set of ceramic cups from a County Clare craftsman), we packed up and headed out.

We were at Shannon Airport in no time at all (I guess we masted this whole "driving in Ireland" thing after all!), and in just a jiffy the car was returned and the bags were checked and we were through security (Shannon is a very small airport and easy to navigate). To kill a few minutes, I enjoyed a pint at the airport lounge while Donna enjoyed the airport gift stores (where they had a lovely scarf).

We arrived at Heathrow, checked in to our hotel, dumped our luggage, and took the Heathrow Express into central London. The train is clean, smooth, comfortable, and fairly fast, but unbelievably expensive: if you buy your tickets at face value, two round-trip tickets will run you 72 pounds (about $130 US dollars), which is an astonishing price for two train tickets from the airport into town. If you buy your tickets online, there is a special deal where two round trip tickets cost only 50 pounds, which is quite a bit better, but it's still almost $90 US dollars. By comparison, the express train from Incheon Airport to downtown Seoul, which travels 3 times the distance but in other ways is very similar, was only $32 dollars for two round trip tickets.

Well, you know: London is expensive, after all. And I really wanted to take the train, because I like to do different things and try different things.

And, as a sort of bonus, the Heathrow Express train takes you to Paddington Station, which I wanted to visit because I so much loved the book when I was a child.

After all of that, we ended up arriving in Paddington Station at 5:00 PM on a Monday evening. Which, if you want to see what Paddington Station is like, is a fun time to get there.

But it's not a quiet time to get there.

Oh, and did I mention that the rain was still coming down steadily?

But then we had a great idea (well, inspired by a suggestion in Rick Steves's book about London): let's take the bus!

Riding the buses in Central London is surprisingly easy.

To start with, you can just use your Oystercard, like you do on the tube. And the bus fare is not bad (typically 1-2 pounds).

Each bus route has a number.

And, in each particular area, each bus stop has a letter, and a map.

The map tells you where bus number 23, say, goes, and how often it stops, and so forth. And, importantly, the map also tells you that, say, bus 23 stops at station K, which is one block to your left.

I'm probably making it sound a bit complicated, but it was really a snap.

And riding the bus at 5:00 PM on a Monday in the pouring rain was actually surprisingly enjoyable. We climbed up to the second floor (in Central London, the buses are double-deckers; you did watch your Harry Potter movies, right?) and watched through the window as everyone was out and about on their business.

From Paddington Station, we rode down Edgware Road, through a large middle eastern neighborhood filled with Lebanese restaurants and markets and lots of cafes with people sitting at tables on the sidewalk smoking the hookah and discussing the events of the day.

We rode down along Oxford Street and watched all the shoppers rushing to and fro.

We came across Oxford Circus and it was a sea of umbrellas.

At Picadilly Circus we decided to get off this bus.

We wanted to do some touristy shopping but nothing in Picadilly Circus was quite right so we took the 19 bus down to Knightsbridge and exited at Harrods.

There is truly nothing like Harrods.

But Harrods at 6:00 PM on a Monday evening, in the rain, in August; well, it was really hopping! Have you ever been shopping in San Francisco, in Union Square, on the Friday after Thanksgiving? Well, bottle all that up, and put it in a single building (a 10-story building that fills an entire city block in Central London), and that's what visiting Harrod's is like.

We actually got some real shopping done in Harrod's. And we also wandered around for an hour or so, to see the toy section, and the fancy restaurants on the top floor, and the famous bronze escalators with the statue of Dody and Diana, and all those other parts of Harrod's that you Just Have To See For Yourself.

Then we walked about two blocks, off the main street and down what seemed like an alley, to a restaurant I'd managed to find on the Internet: Haandi, an Indian restaurant in the North Indian style. The food was superb; the people were friendly; the price wasn't unreasonable: it was the ideal London dinner.

On our long, meandering way back to our hotel, we happened to find ourselves riding a bus with a man from Ireland; it turned out he has a summer home in Dingle and ws there the same day that we visited! It was great fun to tell him about our travels.

Oh, and: I don't exactly know why I feel the need to include this, but we saw the bottle of Dalmore Constellation Cask 1 1972 that is for sale at the Duty Free Store in Terminal 2, Heathrow.

Yes, that price is correct: 13,000 pounds for that single bottle of whiskey.

So, there you go.

After all is said and done, it's hard to think of anything I would want to change about our trip.

Driving in Ireland was, at times, fatiguing, but there's no way we could have seen anywhere close to all the places we visited without having a car. Staying at modern hotels was comfortable, but we didn't spend much time doing the "stay at a traditional B&B, visit a traditional pub, listen to traditional music, meet locals and talk" experience.

Overall, it was a wonderful vacation, and one I think we'll remember for many years.

Ireland day nine: A bunch of Blarney

The day dawns grey and cool, with a steady rain falling. Even the gorgeous pair of Red and White Setters at the Castlemartyr reception desk are looking rather mopey (perhaps they don't get their regular walk in weather like this?).

But it will not get us down: today is our last full day in Ireland and we have a lot planned!

I pack in the Full Irish Breakfast once again, and we pack up the car once again, and we are on the road once again.

Just down the road from Castlemartyr is Barryscourt Castle, recently (2002) renovated and restored by heritage experts from the Irish OPW.

Sadly, an enormous storm in February damaged the electric equipment in the castle and so they cannot admit visitors to the tower house, which is a shame because from all accounts the restoration was particularly well done.

But Robin, the OPW docent on duty this morning, cheerfully puts on his all-weather poncho and gives us a great tour of the gardens and grounds in the rain. His enthusiasm is infectious and even though we don't get to see the inside of the restored castle, I am glad we stopped.

Donna reports that the Pippin apples in the castle garden are yummy; they have carefully planted traditional varieties of Irish fruit trees in the restored orchard, paying as much attention to the authenticity of the garden restoration as they did to the tower restoration.

Our next stop is legendary. Many Americans may not have heard of the Rock of Cashel, but nearly all Americans have heard of the Blarney Stone.

Though I know a lot about it ahead of time, Blarney Castle, it turns out, surprises me. I am taken by three unexpected things:

1. The height of the main castle. The keep itself is more than 90 feet high, and it is built on a large rock bluff overlooking the river, which adds another 30 feet or so to the river-facing face, which makes the overall impact quite dramatic
2. The extent and beauty of the surrounding gardens and grounds. Visiting Blarney Castle involves much more than just kissing the stupid stone: there is a manor house, a number of outbuildings, and hundreds of acres of beautifully-maintained gardens to wander through
3. The particularly clever "Poison Garden," full of medicinal, yet toxic, plants, many of which are quite uncommon and so are fascinating to see growing just 2 feet away from you.

But of course, you're there to see the stupid stone.

So, uncertainly, but with excitement, we enter the castle and begin climbing the stairs. Several times, we have to stop in side rooms and rest, for 10 flights of stone spiral staircase are surprisingly fatiguing.

Finally, we are at the top, and it is overwhelming. You emerge from the tight quarters of the windowless spriral staircase and find yourself standing in the open air, atop the Blarney Castle parapet, 100 feet up in the clear Irish air!

And you barely have time to catch your breath (that is, if your fear of heights allows you to breathe) before you find yourself at the Blarney Stone itself.

Donna eagerly hands me the camera, drops her backpack, purse, and coat at her feet, backs up, lies down, leans back over the side of the wall into thin air and KISSES THE STONE!

I snap 3 pictures, the Castle employees snap 2 more, and down we go.

The Castle is arranged such that you can take your time on the descent, viewing some of the other parts of the tower, but we're so breathless from visiting the top that we pretty much race down.

Still, we linger on the castle grounds for at least another hour, visiting the Poison Garden and the Rock Close and several other sights before we are ready to move on. We linger, knowing that these are mostly manufactured sites, not authentic ones, because they are attractive and enjoyable, but I am drawn on, to find more and truer destinations.

Thus we drive up the roadway through Mallow to Charleville, where we find the turn for Kilmallock.

Kilmallock is a fascinating medieval town, with sections of the city wall still standing, incorporated into the modern houses and shops quite seamlessly, and with several city gates still present as monuments of their own. There is an old friary and a collegiate church here which we explore, accompanied by three young ragamuffins, bored by the inactivity of summer, kicking the dirt and playing throw-a-stone to pass the time.

Now we are on the road again, up through Bruff and Holycross until, after being lost (yes, again), I find the Grange Stone Circle, the largest (114 stone) stone circle in all of Ireland.

Although the circle is large, the stones are smaller and the location less dramatic than at Dromberg, so the overall effect is much milder. Still, we enjoy wandering around, keeping a certain distance from the grazing cows.

Then, just as we are about to leave, I wave a salute to the farmer across the road. He waves back, and slowly walks across the road to meet us.

It turns out that he is the owner of the land on which the circle sits, and he is pleased to talk with us. His name is Timothy Casey, and he spends 20 minutes with us, explaining the stone circle, showing us other sites nearby, and sharing pictures of his children, one of whom has moved away to America. We promise to send him a postcard from the U.S.A.

Time is short, so we bid farewell to Timothy Casey and drive around to the other end of Lough Gur to the visitor center.

There, an extremely enthusiastic docent offers to give us the "5 minute overview"; 20 minutes later she winds down after realizing that we had had about all we could take. But there is a lot to talk about, as this beautiful lake has been the site of human settlement for at least the last 6,000 years, and there are archaelogical and historical sites spanning that entire time (of which the Grange Stone Circle is just a small part).

In addition to the stone circle, we visit archaelogical digs, stone forts, a medieval church ruin, a medieval castle, and, at the end, a "wedge tomb" called the Giant's Grave, carbon dated to 4,000 B.C., far and away the oldest human-created site we've visited in Ireland.

But it is late, and we are tired; we make our way to the Dunraven Arms in Adare, coming full circle. It is just as charming as it was a week ago, though there is no wedding tonight. We have a nice meal in the town pub, relax, unwind, and get ready to travel tomorrow.

Ireland day eight: the Rock of Cashel

Thanks to the M8 super speedway, we make it from Castlemartyr to Cashel in surprising time, and we are at Cashel by 10:00; this will be our only time in County Tipperary.

Then I get lost.

But Donna gets us found again: "patience," she says, as we spot that the sign is actually pointing us down a tiny road that I had taken for a pedestrian walkway the first time through town, so narrow was it.

But just 100 feet down that little lane is the car park, and we are settled, just as three massive tour buses arrive. Well, this is the most-well-known tourist site in all of Ireland, so it is surely no surprise to see them. Let us just say that, when the circumstances require, the good people of Ireland can find room at the loo for all.

We have a nice tour guide, if a little harried (Cashel is simply mobbed, even though we are reasonable early), and he does his best to show us about.

Appealingly, he ends our tour in Cormac's Chapel, perhaps the most spectacular medieval site in Ireland, still holding up quite well even after all the events of the previous 1,000 years.

We pause on the way out to view the pictures from Queen Elizabeth II's visit in 2011, the first visit to Cashel by an English Monarch since King Henry II presided over the Synod of Cashel in 1172.

We walk down into Cashel town center, which is very nice itself, and Donna finds a small cafe which packs us a picnic lunch. We walk about 1 km down the hill with our lunch to Hore Abbey, the last Cistercian Abbey to be founded in Ireland, in 1266.

We are happy: we have finally managed to have our picnic lunch in Ireland (for some reason, this had been eluding us up to this point), and at a place of indescribable history and beauty.

We pop back onto the super speedway and in just minutes we are in Cahir, at the superb Cahir Castle.

Cahir Castle is your perfect dream of a medieval castle; it is hard to imagine any castle that could be better.

It is remarkably well preserved (the portcullis still works, and can be lowered to bar the entrance into the inner keep!), and we get to go everywhere: climb stairs, explore keeps, climb ramparts, descend into dungeons, etc.

A nifty room-size model shows the famous Siege of 1599; cannonballs from that siege are still embedded in the castle walls!.

A seemingly hidden staircase starts by descending toward the river, then ascends sharply and emerges at an outer tower with a commanding view.

It is, bar none, the best castle we have visited in Ireland, and I am happy beyond describing that we managed to include it on our visit.

The super speedway delivers us back to East Cork. We drive down to the oceanside, to Garryvoe Beach, where we walk along a beautiful beach and Donna plays in the waves. If we hadn't stayed at all those other wonderful places on our trip, I would have loved to stay here.

A few kilometers down the road is Shannagarry, home of the world-famous Ballymaloe Cooking School. We tour the school's shop, then walk through the beautiful gardens for 40 minutes or so, seeing barely a quarter of the gardens, focusing on the sections where the students gather fresh herbs and vegetables each day for their classes.

Her recipes are a bit intimidating, though: stinging nettle soup?

The Shannagarry Design Centre has a very nice William Penn museum in its basement; it turns out there is actually quite a bit about William Penn I hadn't known.

We drive down to the end of the road: Ballycotton, with its postcard-perfect lighthouse on an island just offshore. Dozens of people are fishing from the pier: Ballycotton is famous for its seafood. We walk along the cliffs and Donna gathers shells and we watch the fish swim about in the shallow tidal waters.

Then back to Castlemartyr, to rest and unwind.

Each day seems better than the one before, which seems hardly possible.

Perhaps we are getting the hang of this whole traveling thing?

Or perhaps Ireland is simply as magical as everyone has always said.

Ireland day seven: East County Cork

I must not be very practiced at sleeping in hotel beds, even extremely nice ones, because again I am up with the sun. We have a nice breakfast and take our time packing up and checking out, but even so we have left the hotel quite early.

By 9:00, we are at Charles Fort, the largest fort in Ireland and perhaps in all of Europe.

Unfortunately, the fort isn't open for visitors until 10:00.

However, the grounds around the fort are open, and well-cared for, and there are trails along the waterfront, and so we walk here and there, taking pictures, enjoying the views, and soon enough it is 10:00.

Inside, there are several small museums and exhibitions, and more areas to explore, but actually the fort is in many ways better from the outside than from the inside.

In particular, the fort is most interesting when viewed from the Harbor Cruise that we took yesterday: the fort was designed for naval purposes and so its main focus is on the harbor.

Apparently, though, it wasn't really a very good fort, because it kept getting sacked (though thankfully, it wasn't completely destroyed any of those times, or there wouldn't be anything left to see).

Actually, the most entertaining aspect of Charles Fort is the durable legend of the White Lady.

Anyway, no matter how you look at it, our time at Charles Fort was two hours well spent.

Then we drove up to Cork, and, for the second time on our vacation, I made a rather serious mistake about route finding and destination selection. For whatever reason, I took a path which lead us right through Cork City, rather than driving around it on the motorway. I found myself in the inner city, in a section of twisting, one-way, un-marked roads, and promptly got myself badly lost. And that part of town, unfortunately, is the poorest and most unhappy part of Ireland that we visited, so it really wasn't a place where I wanted to stay lost. Happily, it didn't take me all that long to find my way through the neighborhood, and back to a road that I recognized, and get us on our way again.

Still, I'm afraid I don't have any happy words to share about Cork City itself. I wish the residents all the best, and may things improve for Cork City as they have for other parts of Ireland.

We left Cork, and almost immediately took the turn to Cobh. Cobh is certainly not as scenic as Kinsale, but it has at least as much history, and plenty of interesting sights.

Cobh is probably one of the most important cities in Ireland from a maritime history point of view. It was the last stop of the Titanic, but more importantly it was the primary point of departure for many of the emigrants who left Ireland and came to America, Australia, or other overseas destination, a fact memorialized by the poignant Annie Moore sculpture as well as several local museums, including the quite nice Cobh Heritage Centre where we spent about 45 minutes.

Interestingly, Cobh also has an old prison on Spike Island in the harbor, which reminded me of the famous Alcatraz Island here at home.

The Cobh waterfront is quite pleasant to stroll along; St Colman's Cathedral on the bluff above the waterfront is just magnificent.

Our next stop is Midleton, a bustling modern Irish town.

But more importantly, for tourists like us, Midleton is the home of the Jameson distillery, and its very enjoyable distillery tour. The tour is fun, if rather pricey and touristy. The tour winds through the old distillery, which began operations in 1825 and was in regular use until 1975 when the new distillery was built on adjacent grounds. The new distillery is all tall steel-and-glass buildings with piping and fans, but the old distillery buildings are lovely and have been nicely preserved by the company.

Each of the 6 buildings that we visit is a museum of its own, including: the old mill wheel; the enormous kilns for drying the malt (using coal fires, not peat fires: one of the signature differences between Irish whiskey and Scotch); the incredible 3-story tall copper still, the largest pot still ever built; the triple distillation system; and the aging warehouse.

The Jameson Distillery tour was certainly the most touristy thing we did on our holiday, but I'm still glad I did it. It was a nice tour, and it broke us out of a bit of a funky mood and put us in good "spirits" (heh).

We trundle on down the road a few more kilometers east, to Castlemartyr, home of Castlemartyr Resort, our home for the next two nights. It is set on land once owned by Sir Walter Raleigh; the hotel reception, dining and banquet rooms, and other common areas are in the manor house built by the Earl of Shannon (who was the Speaker of the Irish House of Commons at the time); and (of course), just a few meters from the main hotel are the scenic ruins of Imokilly Castle.

The resort is quite modern, and is designed as a golf destination, with a super-luxurious spa as well, but for us the main attractions, beyond the buildings and the comfortable room, are the simply spectacular gardens behind the manor house, and the beautiful pastures and forests that adjoin the main buildings.

If we had not spent 3 days at Parknasilla I'd be raving on about Castlemartyr, but suffice it to say for now that we relaxed, had a drink, walked through the garden, admired the swallows as they raced about, and watched the children playing croquet and racing about on the grass.

Ireland Interlude

I'm not quite sure where this stuff belongs, so I'm putting it here.

• Much of Ireland looks like Northern California. At times, it seems like we could be in Carmel, or Gualala.

  That is, if the money were Euros, the signs were in Gaelic, and you drove on the left.

• In 9 days, we heard 1 airplane. We saw 4 police cars, and a handful of ambulances.

  At home, we see all that in 20 minutes.

• You can't do your own laundry in Ireland. People don't even understand what you're asking for. They will direct you to places where you can drop off your clothes and somebody else will wash them for you, but the concept of a self-service laundromat simply does not exist.

  I'm not sure why this is, but it is.

• Except for birds and fish, there is no wildlife. We saw no signs of deer, raccoons, fox, rabbit, or any of the other various land animals that we live with routinely at home. However, cows, sheep, dogs and cats roam freely everywhere, to the degree that I think the occasional fences were more for humans than for livestock.

  So keep your eyes on the road.

• Everything is ancient. The Irish live amidst millenia of history. At home, we never see anything older than about 200 years, and it's hard to even find buildings that old (perhaps the occasional Junipero Serra mission, say). We marvel at that history, but in the places we visited, it's just there. Which is not to say they don't appreciate it! They just don't treat it as unusual.

  After a while, we realized that every town has a church, or a castle, or a fort.

• The thing about these historic buildings is: how should they be treated? Some are left as is, some are stabilized, but otherwise not much changed, and some are aggressively restored.

  So far as I could tell, within Ireland, some properties are privately owned and the restoration and access to these properties is handled by the owners (e.g., Blarney or Bunratty), while other properties are publicly owned and are handled by the Office of Public Works, or the the Heritage Council.

  Visions of the Past - How Far Should We Go in 'Restoring' Ancient Monuments? asks some very interesting questions about this process and how we should understand and explain it.

  This idea is taken to its limit when it comes to sites such as Newgrange in Ireland. The gleaming white wall that surrounds the entrance to Newgrange is a modern construction, despite the fact that debate continues as to whether the quartzite rocks found on the site were actually used to form a wall, or something else, such as a plaza surface.

  But perhaps concerns over our 'vandalism' of ancient structures is an illusion...after all, in another four millennia, we will be considered yet another ancient people who modified an even more ancient structure, just as King Tuthmosis IV's repairs to the Sphinx a thousand years after its construction (or at least, the orthodox date of construction...) have now become a part of the monument as we know it.

  Of course, part of the fun of looking at the old architecture is to make fun of it!

• Lastly (in this interlude), the answer to a question that nagged at me throughout the trip:

  Why did so many of the old graves say: I H S?

  It turns out, this is easy to answer: IHS Monogram/Insiginia on 18th and 19th Century Gravestones

  According to the New Advent Catholic Encyclopaedia:

  In the Middle Ages the Name of Jesus was written: IHESUS; the monogram contains the first and last letter of the Holy Name. It is first found on a gold coin of the eight century: DN IHS CHS REX REGNANTIUM (The Lord Jesus Chirst, King of Kings).

  (Check out the picture near the end of that article, of the lintel stone from the Augustinian Abbey in Adare.)

Okay, enough of that. Let's get back to the pictures!

Ireland day six: South and West County Cork

We have a nice breakfast at the Carlton, then set out on the road.

After a little bit, we find ourselves in Timoleague, where there is a beautiful old abbey. We wander through it and take some pictures, and leave a small donation (something we've done from time to time at the other places we've visited, when they didn't have a more formal entrance fee).

We drive a bit further, through some small towns, only occasionally getting lost, through Clonakilty and Rosscarbery and down to a place called Dromberg, where there is an ancient stone circle and some Bronze Age ruins.

Okay, I'm not describing this adequately.

Calling the Dromberg Stone Circle a prehistoric site is definitely not doing it justic.

The circle is imposing, and eerie, and startling, and disquieting. It is located on the hillside in a quiet stretch of farmland, with a commanding view down the hills to the Atlantic Ocean.

The stones in the circle are massive; you feel small standing next to these hulking masses. And it's clear, even before you read the signs and walk about and line them up this way and that, they they aren't just randomly placed: they are arranged.

The ruins of two small buildings a few dozen yards from the circle are, in many ways, not so mysterious: they clearly were the foundations of shelter for the occupants, and they hold structures that are fairly self-evident (the sign explains that one of the buildings, which contains a still-flowing well, was evidently built to create a surprisingly useful water pool, which could be heated, even boiled, using stones heated in the adjacent hearth, allowing the occupants to cook food, wash, clean, even just relax).

But the circle is more frustrating: it just sits there, challenging you with its presence, existential proof of some great purpose to justify such great effort, but mute about the details.

Some stones are horizontal, some are vertical; some are aligned with nearby landmarks; some are aligned with celestrial landmarks; some appear to create openings or passages.

But what does it all mean? We sit, and stroll, and look, and muse. It is moving, that's for certain.

We leave Dromberg and return to Clonakilty.

Clonakilty is close to the perfect Irish village, in my opinion. It has all the charm, beauty, setting, and atmosphere of towns like Dingle, Kenmare, Killarney, Adare, or Kinsale, but it is mostly unspoiled by the tourist crush. There are no tour buses, no gaudy trinket shops, no fighting your way through streets to crowded to walk down.

And don't forget about Clonakilty Black Pudding, part of your perfect Irish breakfast!

We walk for a bit, looking at the stores and houses, buying a bag of sweets, enjoying the town, until it starts to rain. Then we pop into Scannell's Pub for a just-right pot of tea and a chocolate brownie with clotted cream, sitting happily at the bar and listening to all the locals come through and chat with the barman about the latest news of this and that.

We leave Clonakilty intending to find a stone fort nearby, but I don't have the directions right, and instead we find ourselves at the Michael Collins Centre. I'd call it a labor of love but I think it would be more accurate to call it a labor of family history. It is a converted farmhouse, owned by descendants of Collins, who have assembled an extensive collection of information about his life and times.

We park, and pay an admission, and are ushered to a room which has been converted to an auditorium, where a gentleman is narrating a slide show about Collins.

He is extremely well-informed about Collins, and extremely engaging, but there is only so much information that we are prepared to absorb about Collins, so after about 45 minutes we decided that we had to move on, and took our leave.

We returned to Kinsale, getting back just in time to take the harbor cruise, a peaceful trip through the beautiful harbor, accompanied with a nice narration to explain the fabulous views.

After the harbor cruise, we took a short walk through some of the sections of Kinsale that we had missed the previous evening. Desmond's Castle, though not much of a castle, has some fun history to go with it, while St. Multose Church, still in good condition and still in regular use, was built, amazingly, in 1190 A.D.

It was in this church that Prince Rupert proclaimed Charles II as King, after hearing the news that Cromwell had had King Charles I executed in London.

We find an Indian restaurant on a side street of Kinsale where we have yet another yummy dinner, then return to the hotel for an evening swim and a drink at the hotel bar, with its glorious view of nearby Oysterhaven Bay at the mouth of the River Stick (yes, there is a River Stick; it joins Belgooly to Oysterhaven Bay. So there.).