Chocolate fireguard
Active member
hyweldavies said:
Speed.
A complete statement of velocity must include speed and direction. For example:
3 furlongs/fortnight north.
5m/s vertically downwards.
Obscure units
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Speed.
A complete statement of velocity must include speed and direction. For example:
3 furlongs/fortnight north.
5m/s vertically downwards.
Subpopulus Hibernia
Active member
You young ones have it easy - back before the metric system every country had their own system of measurement, and in fragmented places like Germany, each canton had its own foot or yard. We had it tough caving back then. Saying that a cave was a mile long was a very different thing to a Prussian as opposed to a Castillian, with the Prussian having nine miles to the Castillian's one.
I remember trying to draw up Gr?neschweinh?hle from Karsten van Adelstropp's notes in 1773 - of course you might expect that he would have measured the place in Klafters, but the only tape he could get a hold of was an old miners measuring chain which used Lachters. So, to make things easier for me, Karsten converted all the measurements to Swabian Feet (since I was in Grenoble at the time, using the pre-revolutionary French measurement of the Toise (seven Swabian feet was exactly equal to one Toise, therefore easier to convert than the more commonly used Silesian Foot (which went into one Toise 6 and three-fifths times))). However, I assumed that Karsten, being a Bavarian, would use the Bayruthean Foot (seven and one sixth to one toise), so I converted all of his measurements to the French system, which meant that every measurement was out by one 'Pied Royale' in every seven Toise. To make matters worse, Karsten wrote to me that winter to tell me that he'd discovered the measuring chain he'd used was made in Darmstadt, so it was probably based on the Hessian Lachter, which was one Zoll (about an inch), longer than the Bohemian Lachter that he though it was. At first I tried to correct the scales by rounding up or down each Pied Royale to the nearest Pouce, and then converting the lot to Amsterdam Feet, using the table at the back of and old copy of Zijkermeyer's Mercantile Almanac. But this I discovered pre-dated the Dutch measurement standardisation of 1767, so I scrapped that, and used a log table to convert all the measurements to decimal fractions of the Swiss Mile (on account of the Swiss Mile being exactly equal to 468 Toise, and therefore possible to use a base of 4.5 to calculate the exponent (or vice versa, which was why distances from Lucerne and Geneva to French towns and cities were often given in duodecimal fractions of the Toise).
At the end of all of this the centreline was plotted on a linen sheet about two (Scottish) fathoms across, with scale bars for Dutch Roeden, Thuringinan feet, French (i.e. Parisian) Miles and Castillian Yards. The engraver nearly had a fit when he saw this, but I managed to use a Camera Obscura to reduce it down to fit onto one Double Demy sheet, and we got the survey printed in time for that years Journale Francaise d'Geographie.
Another problem was disputed measurements - in 1781 the Belgians (Part of the Spanish Netherlands back then) claimed to have the deepest cave in the world (Grotte d'Agositina) at a depth of 88 (Dutch Standardised) Roeden. The Swiss claimed that Brutenh?hle was deeper at 7845 Helvetican Inches, claiming that the Belgians were (somewhat sneakily) using the Pre-standardisation Rotterdam Roede, giving it an actual depth of 79 (Dutch Standardised) Roeden (about 23 metres in modern parlance). As it turned out, the Swiss were correct on the measurement side of things, but as we now know, the Grotte d'Agositina was actually a medieval soil mine, something that was hard to make out with the poor lighting that we had back then.
I remember trying to draw up Gr?neschweinh?hle from Karsten van Adelstropp's notes in 1773 - of course you might expect that he would have measured the place in Klafters, but the only tape he could get a hold of was an old miners measuring chain which used Lachters. So, to make things easier for me, Karsten converted all the measurements to Swabian Feet (since I was in Grenoble at the time, using the pre-revolutionary French measurement of the Toise (seven Swabian feet was exactly equal to one Toise, therefore easier to convert than the more commonly used Silesian Foot (which went into one Toise 6 and three-fifths times))). However, I assumed that Karsten, being a Bavarian, would use the Bayruthean Foot (seven and one sixth to one toise), so I converted all of his measurements to the French system, which meant that every measurement was out by one 'Pied Royale' in every seven Toise. To make matters worse, Karsten wrote to me that winter to tell me that he'd discovered the measuring chain he'd used was made in Darmstadt, so it was probably based on the Hessian Lachter, which was one Zoll (about an inch), longer than the Bohemian Lachter that he though it was. At first I tried to correct the scales by rounding up or down each Pied Royale to the nearest Pouce, and then converting the lot to Amsterdam Feet, using the table at the back of and old copy of Zijkermeyer's Mercantile Almanac. But this I discovered pre-dated the Dutch measurement standardisation of 1767, so I scrapped that, and used a log table to convert all the measurements to decimal fractions of the Swiss Mile (on account of the Swiss Mile being exactly equal to 468 Toise, and therefore possible to use a base of 4.5 to calculate the exponent (or vice versa, which was why distances from Lucerne and Geneva to French towns and cities were often given in duodecimal fractions of the Toise).
At the end of all of this the centreline was plotted on a linen sheet about two (Scottish) fathoms across, with scale bars for Dutch Roeden, Thuringinan feet, French (i.e. Parisian) Miles and Castillian Yards. The engraver nearly had a fit when he saw this, but I managed to use a Camera Obscura to reduce it down to fit onto one Double Demy sheet, and we got the survey printed in time for that years Journale Francaise d'Geographie.
Another problem was disputed measurements - in 1781 the Belgians (Part of the Spanish Netherlands back then) claimed to have the deepest cave in the world (Grotte d'Agositina) at a depth of 88 (Dutch Standardised) Roeden. The Swiss claimed that Brutenh?hle was deeper at 7845 Helvetican Inches, claiming that the Belgians were (somewhat sneakily) using the Pre-standardisation Rotterdam Roede, giving it an actual depth of 79 (Dutch Standardised) Roeden (about 23 metres in modern parlance). As it turned out, the Swiss were correct on the measurement side of things, but as we now know, the Grotte d'Agositina was actually a medieval soil mine, something that was hard to make out with the poor lighting that we had back then.
Bottlebank
New member
Superb! All is now clear!
That would be a great point to lock this thread at
That would be a great point to lock this thread at
Subpopulus Hibernia
Active member
bograt said:
Someone (I think it might have been Voltaire) once told me that that in the Medieval period the 'Pied Royale' was simply a courtesy term and most French regions used customary measurements. Certainly, some time in the late 1400s some one of the more meglomaniac rulers in the House of Valois insisted that the measurement correspond to the length of his right foot. His successor also insisted on the the same privelige be applied, to the dismay of merchants and craftsmen, who had to purchase new measurements. This went on as far as King Baptiste IV, who lost the top of his right foot to gangrene after a horse trod on it at the Battle of Goinard. This meant a further shortening of the pied royale to just under four Provencal inches. The House of Valois were never known for their stature to begin with, so this was a very short foot indeed, prompting the mockery of neighbouring kingdoms (it is believe that John Skelton's 1527 satirical poem, 'Ye Ffrenchmanse Lymp' refers to this situation). This particular recalibration prompted the Watchmakers Riots in Nante of 1522, which was bloodily supressed. A futher complication arised with the investiture of Prince Remi XII, at the age of 6, requiring recalibration of measurements on a yearly basis to account for the young King's growth. Finally, the wealthy merchants of Liege (still fired up with the ideals of feedom and autonomy following the cessation of the the Liege Wars of the fifteenth century) stormed the Hotel de Ville, siezed the Mayor and demanded that the incessant recalibrations cease at once. After tense negotitations led by the Duke of Lorraine, it was decided to set the 'Pied Royale' at a equivalent to nine French Inches (and later 11 French inches following the Concordat of Turin)
ALEXW said:Just don't even think about using these measurements whilst playing Mornington Crescent
Although Subpopulus Hibernia could claim a point if he was playing the pre-revolution version.
Funny you should mention Mornington Crescent ? when I lived in Regensburg in the 1750s we played a game called Koenigstrasse, which was essentially the same as Mornington Crescent, but it used the Westphalian Coach Network rather than the Tube, and it was a lot harder to use the inversion rule to reach the border with the Netherlands when the distances didn?t have a decimal base. Some would say that decimalisation ruined Koenigstrasse, and was a major contributory factor to its decline in the early nineteenth century, but I've always pointed out that the popularity of Mornington Crescent in the twentieth century shows that this isn?t the case. Then again, we had to play the game before George Boole demonstrated mathematically how the routes could be traversed without recoursing to the inversion rule, a development that opened the game up to the masses by allowing use of conditional theory to double the points on backward traverses, which did much to add to the excitement and playability of the game.
As I recall Koenigstrasse was popular for a while using a simplified version where the numbers were rounded. However what started as a simple dispute over whether point 5 should be rounded up or down soon became very heated. This caused most right thinking people to learn the rules of Mornington Crescent and leave Koenigstrasse a minority pastime.
hyweldavies
Member
bograt said:
And didn't the game lead the great Mr Euler to invent topology, a whole new area of mathematics ?