Old School Data Mining, Maritime Style? 236
jason0000042 writes "The BBC is reporting on Cliwoc, the Climatological Database for the World's Oceans, which pulls data about climate change from 18th and 19th Century sailing ships' logbooks. It's like a window in time that could help us better understand global climate change, if they can decipher the olde timey language of the 1750's. Personally, I can't wait to know if we're going to melt down, or alternatively, have an ice age."
'tis good (Score:5, Funny)
I, fore won, (Score:4, Funny)
Old School Data Mining, Maritime Style? (Score:4, Funny)
I pictured rovers being smashed into a database.
AARRRGH!!!! (Score:2, Funny)
I'll keel-haul ye varmits!
-Blackbeard
oldish lameish joke: (Score:2)
The Captain's log. ahhhh ha ha ha ha.
Please... (Score:5, Insightful)
Personally, I can't wait to know if we're going to melt down, or alternatively, have an ice age.
Unfortunatelly the data sample being studied is insufficient to give you an answer for two main reasons:
1. The data is more complete for the Atlantic Ocean. A big chunk of the Pacific Ocean is left out simply because the most interesting travel routes were concentrated on the South Pacific.
2. 100 years of weather records are insufficient to make accurate predictions of global climate patterns.
I, for once, would be grateful if /. editors and contributors refrained of making comments like these in the stories.
R.Oh puh-LEEZ! (Score:3, Informative)
Actually, they kept very complete records, as was required to establish best times of year to sail and what to expect. 100+ years of that information can help indicate if there's a trend or we are simply seeing spikes.
El Nino has been considered as evidence of global warming, however, there are records of extreme rainfalls along the west coast of California back in the late 1800'
Re:Please... (Score:3, Insightful)
The 100 years by itself may not, but add to that the 150+ years (1850 - present) that were measured via more traditional means, and you start to have something a little bit more solid.
Re:Please... (Score:5, Insightful)
Re:Please... (Score:4, Insightful)
Re:Please... (Score:2)
Pfft... Global weather prediction with only
old timey language (Score:4, Funny)
I'll help bridge the language gap in words all slashdotters can understand
Yar! Shiver me timbers matey, there be a seaman on the poop deck = first post, nautical style!
Avast me scurvys = why the hell didn't we bring any women on this 12 week voyage? My nuts feel like cannonballs!
Global Warming... (Score:3, Insightful)
Re:Global Warming... (Score:5, Insightful)
Sleepwalking through history (Score:3, Interesting)
Any even passing knowledge of history, just little old human history, will show you the sorts of catastrophic social changes that occur as a result of serious climate change. The Mfecane in SE Africa was a massive migration caused by climate change there: Shaka Zulu was the end result. Krakatoa erupting around 535 A.D., affe
Re:Ignore it? That IS the best action (Score:2)
Sure beats playing Chicken Little.
Here's another fellow who refused to be a "Chicken Little." [chron.com] You guys rock!
Of course it isn't the end of the world! (Score:2)
It is humanity that will suffer as our coastal cities get flooded or our fertile plains become desert or our valleys become lakes.
Science is helps us understand, predict, prevent, and change in our favor our environment. The whole brouhaha is whether we are making things worse *for ourselves* or whether we can somehow make it better.
Yes, it is nice to protect the Earth; I believe in that, but a lot of people seem to need the additiona
Re:Of course it isn't the end of the world! (Score:2)
Re:Of course it isn't the end of the world! (Score:3, Interesting)
The thing that the "we're all going to die!" extremists miss, is that the changes will happen over a very long period of time. e.g. In 5 years, the shore may creep up 10 inches. If it starts becoming a problem, you'll find that governments will start building dykes, or digging shoreline trenches to keep the water at bay.
To anyone who thinks this sort of terraforming is a big deal, you need to take a trip to visit Superior-Deluth on the bo
Re:Of course it isn't the end of the world! (Score:2)
The thing that the head-in-the-sand extremists miss, is that climate changes could happen very quickly - extreme inputs could push chaotic atmospheric and ocean current systems over to another attractor. For example, there is the possibility that the Gulf Stream will be stopped by meltwater from the arctic (see this thread [slashdot.org]).
Re:Of course it isn't the end of the world! (Score:2)
Re:Of course it isn't the end of the world! (Score:2)
Arguably, if we don't progress technologically, then the Earth's natural storms and floods will get us. If we *do* progress than we have a better chance of surviving the storms and floods indirectly caused by our progress.
But I agree. "eco warrior types" as you put it, worry
Re:Of course it isn't the end of the world! (Score:2)
This works great for Holland, or for small areas of countries (such as the example you provide). However, the total shoreline of the United States is huge! It would be the largest engineering project to date to reinforce the shorelines of the entire country. If a large rise in the water level did occur, I would suspect that not all of the shoreline would be protec
Re:Of course it isn't the end of the world! (Score:2)
Most of the West Coast U.S. remains pretty much undeveloped. However, the East Coast U.S. is pretty well developed up and down. Much of this development is in the form of harbors. If you look at it from the perspective of every harbor hiring a few trawlers or dyke buil
Re:Of course it isn't the end of the world! (Score:2)
May I direct your attention to that pretty arch of light in the sky known as a "Rainbow". I believe it has some cultural significance to your plans.
Re:Of course it isn't the end of the world! (Score:2)
http://mindprod.com/kyoto.html [mindprod.com]
It sounds like one of the most contrived schemes I have heard of yet. The cost figures parent gave don't surprise me one bit. On the bright side, maybe we'll start building some modern Nuclear Plants instead of working to simply shut down all the 1960's plants.
Re:Of course it isn't the end of the world! (Score:2)
Re:Of course it isn't the end of the world! (Score:2)
I said what I said, and I mean what I said. Unless someone hits the ice caps with a giant blow-torch, there's just no way that the "sea-level" would rise 2 inches per year.
Re:Of course it isn't the end of the world! (Score:5, Insightful)
*cough*bullshit*cough*
You do realize that the overpopulation fears of the 1970's never materialized? The population was supposed to grow to over 7 billion during the 80's. It didn't. In fact, many countries are depopulating due to the modern attitudes toward having children.
Most of the people out there who are starving are in countries where no economy has been imposed to foster the supply of goods. We have more than enough food here in the U.S. to feed most of Africa, but there's no economic incentive to do so. Throwing monetary "aid" at the problem only makes those people dependent on our kindness instead of improving their life-style.
I should probably also point out the tremendous amount of undeveloped land in Russia and China. Russia has two major cities: Moscow and St. Petersburg. Most people living outside of those areas are poor farmers that perform their duties with the equivalent of 1850's technology. Many of the tractors and combines they do have, are built to double as war vehicles! (Gotta love the thinking the Communists had.) Thus, everyone wants to live in Moscow. They only go to St. Petersburg if they can't get to Moscow.
China isn't much better. Everyone is crowded into the cities while hundreds of thousands of acres of land are left to be tended by townsfolk who haven't seen much technological progress in 400+ years.
If you look at U.S. history (as a comparison), land development has been fostered by capitalism. The government's grant of homesteads encouraged individuals to develop land for profit. Thus very little usable land has been allowed to sit like it has elsewhere.
You read Lomborg and decided you're an expert, eh? (Score:2)
This is the kind of statement I expect from people who've read one book on the subject in their lives. It ignores the myriad reasons why that land isn't already developed from the 5,000 years of Chinese civiliz
Re:You read Lomborg and decided you're an expert, (Score:2)
Who?
This is the kind of statement I expect from people who've read one book on the subject in their lives.
Actually, my wife is from Russia. Nearly all of her family are biologists, and her aunt and uncle work with the farmers across the "far east" (the area from the edge of Asia to China) to preserve cranes.
Also quite a few of my friends are chinese. It's quite interesting how different regions contrast one another. Some chinese are quite adept with m
You haven't refuted my point, you know (Score:2)
I notice that Alaska is not a significant producer of corn. Or wheat. Or rice. Or soya, or grass-fed beef, or wool and mutton, or anything else that America relies on to feed itself. The long summer days which can make amazing hothouse tomatoes don't translate to much in practice; the temperate rain-forest conditions north of British Columbia are great for forests but not food. I note that Alaska's major industries are fishing,
Re:You haven't refuted my point, you know (Score:2)
Why should they? Amercia uses its fertile lands very effectively. With the number of farms *shrinking* in the U.S. (a sad state of affairs), why would anyone grow exports in Alaska? If there was actually a serious food crunch, then those giant vegatable might come in handy. Otherwise they're just an oddity.
The Imperial Valle
Re:Of course it isn't the end of the world! (Score:3, Interesting)
Oh, cry me a river. We change the environment just by existing. The primary difference between the way we change it and animals change it, is animals find their niche for adding balance, and stop there. Humans continue to change their environments more and more, but as a price must learn to complete the cycle.
Thus "defore
Re:Of course it isn't the end of the world! (Score:3, Insightful)
You define deforestation as cutting of old trees and encouraging growth of new ones, then imply this is little different than the whole area being wiped out by a forest fire. There are many misconceptions in that opinion.
1) This is the US model of "deforestation", whereas most deforestation happens in rainforests where the forest is clear cut and burned to ash, and the ash then provides nutrients for crops to grow. If this is just a small p
Re:Of course it isn't the end of the world! (Score:3, Interesting)
Interestingly, there was an article a while back that suggested that the reason the South American rain forests grow as well as they do is because early indians cultivated the soil for farming. A similar situation is believed to be true [theatlantic.com] for North
Re:Of course it isn't the end of the world! (Score:2)
That's great and everything, but I was talking about today's technology. We can already superheat any material into a plasma. In that state, molecular bonds can't be maintained. Thus you can separate and recombine freely. The core problem is energy. It takes a freaking lot to do that stuff! B
Re:Of course it isn't the end of the world! (Score:2)
After having viewed alerce trees over a thousand years old in Chile and redwoods and sequoias in the U.S. of similar age, I can assure you that your view of fire is simplistic and. in many geographic areas, just plain wrong. Many mature forests survive repeated fires, and often rely on them to clean out the
Re:Of course it isn't the end of the world! (Score:2)
No, animals don't do that, they don't stop. The *environment* forces the balance, generally by having a lot of animals to die... There's no inherent balance in the nature, other, there's only survival. If balance leads to better immediate survival, then it'll
Re:Of course it isn't the end of the world! (Score:2)
Did you ever stop to think that maybe we shouldn't play god everytime. We screwed it up and you think we can fix it just as easily.
So we should just play God when it suits you? When is that? When someone is making a profit? Then it's OK to play God by adding trillions of tons of Carbon Dioxide to the atmosphere? It seems like the logical thing to do would be to stop altering the composition of the atmosphere if we don't know exactly what the effects are.
Maybe a good flood would do everyone a favor.
Obligatory Dilbert joke (Score:4, Funny)
Let's do both!
Re:Obligatory Dilbert joke (Score:2)
Let's do both!
Don't laugh...it could happen... [dinosauria.com]
Re:Obligatory Dilbert joke (Score:2)
The first thing to happen with global warming will be a Gulfstream stop. Most of Europe will freeze outright. The current models are for 9-11C lower on year averages in England and around 7-9C around the North Sea - Germany, Denmark, Belgium, etc.
At the same time Central America will get fried as the rainfall band goes north and near desert conditions descend on the Mexico and Panama. Texas will become cooler and more humid, so on so forth.
Ever w
Other stories about Ancient Climates and GW (Score:3, Interesting)
http://www.smu.edu/newsinfo/releases/99355a.html [smu.edu]
Hunt is on for ancient 'global warming' documents
http://www.ananova.com/news/story/sm_787743.html [ananova.com]
Warming AND Ice Age (Score:5, Informative)
The basic gyst is that the warming melts Greenland. This diverts the gulf stream; plunging Europe into an Ice Age. [It also cools the NE of North America, but Europe really gets it.]
The average temperature is rising, that doesn't mean it's getting warmer everywhere.
Re:Warming AND Ice Age (Score:5, Interesting)
The basic gyst is that the warming melts Greenland. This diverts the gulf stream; plunging Europe into an Ice Age.
To be more specific, the meltwater coming off a warmer Greenland will dilute the seawater at the terminus of the Gulf Stream. The Gulf Stream is driven in part by salinity differences (hence the term "thermohaline circulation), and if the dilution reduces the magnitude of these differences too much, then it is possible that the Gulf Stream will shut down. A good introductory discussion of this subject can be found here [guardian.co.uk].
To see what Europe might be like without the Gulf Stream, consider that the British Isles are at the same approximate latitude as Newfoundland. Brrrrr!
Re:Warming AND Ice Age (Score:3, Insightful)
There was a paper in October of '02 outl
Re:Warming AND Ice Age (Score:3, Informative)
So you'd better watch out...if you don't play nice, we'll take the Rockies down
Hah, if you do that, then we'll blow La Palma [bbc.co.uk] and watch the US east coast disappear under a tsunami over half a kilometre tall! In fact, we don't need to blow it; according to this article [benfieldhrc.org], the collapse of La Palma becomes more likely as global temperatures rise.
However, there's no cause for panic. I have a friend working at the Instituto de Astrofisica de Canarias [www.iac.es], and he's promised to phone me if La Palma collapses. I'll
Re:Warming AND Ice Age (Score:2)
Re:Warming AND Ice Age (Score:2)
It seems that that such seemingly small change of a single degree (Celsius) might actually do this. Once a firm believer man was doing all of this I'm not all that sure anymore. All told nature always wins and from that point of view we are not much of an influence.
This does
Re:Warming AND Ice Age (Score:2)
How exactly would $4/gallon be fair to anybody but B.P. stockholders?
Re:Warming AND Ice Age (Score:2)
How would your driving habits change in the long term if gasoline prices tripled or quadrupled and your fuel budget did not?
Re:Warming AND Ice Age (Score:2)
How exactly would $4/gallon be fair to anybody but B.P. stockholders?
How would your driving habits change in the long term if gasoline prices tripled or quadrupled and your fuel budget did not?
Not at all, to be quite honest, and how does that answer my question?
This dovetails nicely with... (Score:3, Interesting)
Ship's Log (Score:3, Funny)
Januarye 17, 1787
Anchored at Shanghai bye night, traded opium for much filver, failing for Hong Kong on the tide. Temperature 65.
Januarye 21, 1787
Anchored at Hong Kong, but were vifited by cuftomef officialf. Snuck up a river by night to fell more opium to chinefe for silver. Got very nice candelabra for the wife. Temperature 61.
January 24, 1787
Macau not welcoming our bufineff, but fnuck up a river by night and fold laft of opium for more filver. Blimey, what racket, time to head back to Tonkin. Temperature 62.
Mexican silver (Score:2)
Actually, by then China was so developed and so self-sufficient that the only noteworthy imports were silver and opium. It was the European countries who wanted to trade all the fine Chinoiseries.
So, did the Chinese really trade back silver?
The easy solution is pollution (Score:3, Interesting)
If they are worried about the Great Ocean Conveyor giving out in the Labrador Seas due to an increase in freshwater runnoff, (there is evidence to suppor that this happened during one of the last ice ages, when a ice dam broke and billions of gallons of fresh water dumped into the North Atlantic, shutting down the Gulf Stream, and turinng a gradual thaw into a deep freeze,) there is a simple solution, should this be found to be the problem.
Dump lots of dense, salty crud in the North Atlantic!
This will help keep the water sinking, drawing more warm water up from the Gulf, and incedentally keep Europe warm. Where to get this water densification material? Why good old fashion pollution, of course.
Heavy metal salts, and any industrial ionic or polar goop that readily disolves in water can be spread by the tanker load accross the Labrador and Greenland Seas, increasing the density of water, and compensating for the freshwater runnoff that is occuring as a result of global warming.
The normal quote in industry is "The solution to pollution is dilution" Well, in this case, "The solution to dilution is pollution!"
Re:The easy solution is pollution (Score:2)
Dump lots of dense, salty crud in the North Atlantic!
New eco-slogan: Save the planet! Pull yourself off into the North Atlantic!
Sufficient Range? (Score:3, Insightful)
reading logs (Score:4, Funny)
Re:reading logs (Score:2)
You'll have both (Score:4, Insightful)
So what you are asking are what effect human activities (air/sea pollution, cutting down rain forests) have on current climate, and on the climate in the next few decades. Most scientists, except Bush croonies paid by the oil industry, agrees that pollution has increased temperature.
Most likely, it'll be your grandchildren that will see the worst of the effect. Except, of course, countries that is very flat on just above sea level, like Bangladesh, are already hit. But then again, poor people in the third world does not matter, eh?
Re:You'll have both (Score:2)
nice Troll but... (Score:2)
by the time DDT was banned in industrialized countries, it was already fairly ineffective against mosqutoes, due largly to over use. In fact most pesticides are only effective for a few years before the pests they are designed to kill evolve effective defenses against them. DDT just also killed birds so it was banned before it no longer killed any insects.
German Cockroaches are an Endangered Species! (Score:4, Insightful)
Re:German Cockroaches are an Endangered Species! (Score:5, Insightful)
However, until it's clear whether human activity or climatic cycles are causing the warming, doesn't it make sense to reduce the emission of greenhouse gases? If the doomsayers are wrong, well, at least we've reduced pollution (which most greenhouse gases are, btw). If they're right, we're better off than we might have been. Think of it as taking out an insurance policy.
By the way, you may have noticed that the ozone hole isn't in the news as much anymore. There's a reason for that -- since our industries have stopped emitting CFCs in such incredible quantities, the hole has slowly begun to close itself up again. It's going to take a while before the ozone layer is 100% "healthy," but it's a good example of how the correct steps taken can begin to correct a problem.
false claim (Score:2)
B.S. The largest ozone hole on record was in 2000. The second largest was this year [sciencedaily.com]. There's too much inter-year variability to make such a claim. Perhaps the Earth's weakening magnetic field will allow in more electrons, which have been shown to destroy ozone [sciencedaily.com].
Re:German Cockroaches are an Endangered Species! (Score:2)
Not necessarily. Efforts to reduce greenhouse gasses may, in fact, have no significant effect on global climate. They may, however, be significantly disruptive to the economy, particularly in poorer nations. Oddly, only the very wealthy are concerned about climate change and the environment. Poor people are usually more concerned about clean drinking
Both (Score:5, Informative)
The weather has been demonstrated conclusively to be a chaotic system. One feature common in chaotic systems, easily seen in the Lorenz simulation (e.g. in your screen saver) is that when the system's oscillations get increasingly large (a little moreso each cycle), this is prelude to a change in mode to a different attractor, where all recent history has no predictive value at all.
Imagine what would happen if the Gulf Stream decided to flow on a different path, e.g. because of the massive salinity decrease around the north pole. The end of agriculture in northwestern Europe is just a beginning. Anybody who thinks that ocean currents can only flow the way they do now is very silly indeed.
Funny, lots of shipping company executives are excited about the prospect of driving across the north pole.
Dont want to be a stick in the mud as it where but (Score:2, Interesting)
Isnt the fact we cant even decipher 1750's English a testament to our inferiority at predicting the weather.... not to speak of the fact Ive never known a single weather reporter to give a accurate forcast of the weather.. well now thats where I slip up
Gotta love this weather thing.
let the ice come... (Score:2)
I reather have an ice age. since i live in a tropical place is unlikelly that ice will cover here, in a worst case scenario we'll have a climate resembling that of southern chile or argentina (snow in winter, warm in summer). plus, my sister lives in a litoranean city. if the ice caps melt (specially the southern one) her city will drown.
Aliens Cause Global Warming (Score:5, Interesting)
Since this discussion will lead to the inevitable global warming flap, this paper offers a good viewpoint on the issue (although I disagree with his assertion that SETI is a religion - it isn't - it's an experiment).
A few quotes:
Regarding Sagan's claims of nuclear winter:
Although Richard Feynman was characteristically blunt, saying, "I really don't think these guys know what they're talking about,"
In my book, if Feynam said it, it was almost certianly true. I used to go to his lectures at Hughes Malibu Research Center and it was an amazing experience.
I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you're being had.
Re:Aliens Cause Global Warming (Score:3, Interesting)
Re:Aliens Cause Global Warming (Score:2)
Although political pressures are important, I think it's the journalistic pressures that predominate. Bad news sells papers. Scientists are as prone as the rest of us to getting the overall impression that things are getting worse, because bad news travels faster than good news and sells bet
Re:Aliens Cause Global Warming (Score:2)
Okay, then, I'll send my next grant proposal to Time Warner instead of NSF. Thanks.
Re:Aliens Cause Global Warming (Score:2)
(Note I've reversed the order of the sentences in the original post.)
The problem I have with this logic is that it does not follow. There's only three basic predictions to make on climate issues right now, "It'll get warm
Re:Aliens Cause Global Warming (Score:2)
Clever, but wrong.
This isn't about a prediction of the sign of the change. It's about a prediction of unnaturally rapid change, mostly in high latitude continental interiors. Been
Re:Aliens Cause Global Warming (Score:2)
Re:Aliens Cause Global Warming (Score:2)
Re:Richard Feyman, the scientist (Score:2)
The quote says nothing whatsoever about Feynman's opinion about greenhouse-gas mediated climate change.
Battlefield Detective .. (Score:2, Interesting)
Weather Control Technologies (Score:2, Funny)
It seems that Star Trek inventions become real inventions 20 to 30 years after the original broadcast date. This is not hard-tested theory, but something I am researching.
By my reconning, the weather control systems mentioned in TNG (circa 1995) will be implimented sometime between 2015 and 2025. So as long as we can keep global warming from getting out of hand until them, we should be coo
Re:Weather Control Technologies (Score:2)
Bucket correction factor (Score:3, Informative)
According to the guy this causes one of the biggest uncertainties in todays climate models! They try to compensate this by fudging with the so called bucket correction factor [noaa.gov].
Re:Bucket correction factor (Score:2)
First thing I thought of -- Ships' logs took weather damn seriously in the age of sail, but all the various experimental instruments to gauge salinity and temperature at different depths and so on would be just crazy to try to work with now. (Humboldt would be so proud to know we're using his stuff, but he was hardly confident in the results he got even then.)
We're talking about
Gibbon (Score:2)
Yeah, I see what you mean. Most people wouldn't understand a word of it.
KFG
How does this help? (Score:2)
Re:How does this help? (Score:2)
That 10,000 year cycle was sustained without human pollution.
Depending on how much of an influence we are, the cycle could be modified.
In that sense, those 400 years are important.
The politicians can't make informed decisions without the help of science.
-metric
But... (Score:2)
Human-induced atmospheric change is a scientific topic. People want to keep debating the effects of the changes we're making to the atmosphere. Why are the changes themselves not debated? Wouldn't it be prudent to avoid changing something that our lives depend on -- especially if the effects are uncertain?
Re:Ice age caused by global warming? (Score:2)
2.) The thinner the ice, the faster/quicker/sooner the water underneath gets sunlight...this results in warmer lower layers of floating ice, which results in faster melting of all layers. Rince and repeat....each cycle is shorter/faster.
An accurate weather forecast, for once. (Score:5, Funny)
I think this is a weather forecast we can't go wrong with! Would it be safe to say that there is a 100% chance of hail at some time during these future decades as well?
Re:I was a National Weather Service researcher (Score:2)
Dunno where you live, but in the Northeast, it is quite the opposite, which would actually support your conclusion, imo. It is pretty much just an increase in the heat-island effect. Asphalt heats up during the day, and retains that heat into the evening hours, resulting in higher temperatures near the ground. As more people move out of the city, more pavement is required in what used
Re:I was a National Weather Service researcher (Score:4, Informative)
Re:It's worse than I thought (Score:2)
Although we may need to wait another decade or so to confirm wherever or not there is global warming.
Re:Acuracy (Score:2)
Re:Acuracy (Score:2)
Keep in mind that most of what I know about seafaring comes from reading Shogun and Tai-Pan.
It shows.
Cheers,
Re:Acuracy (Score:2)
You still have to know what direction the wind is going in order to get your boat where you want it to be. Or have I completely misunderstood the nature of sails?
Re:Acuracy (Score:3, Informative)
The tools that they used were briliantly simple and delivered reasonable accuracy as long as they were well treated. Even today, the sextent is used to confirm the locations of bouys and etc because it can independantly confirm the GPS reading. Windspeed was guaged with a spinning cup or a paddle. The spinning cup method depends on the accuracy of the count and time, and the paddle method depends on the accuracy of the paddle's measurements and it's precise weight. Since the shi
Re:Acuracy (Score:2)
Actually you have that backwards ... deadreckoning depends on knowing your speed and direction. Speed was measured directly by tossing a float overboard - originally a "log" - and counting knots on a rope for 25 seconds, giving you the ships speed in (hang on now!) "knots". The line was scaled so each knot counted represents one nautical mile traveled in one hour.
This speed, along with compass bearing and import
Re:Acuracy (Score:2)