THE BRITISH ME'TRE, &c. The two chief units, which nature offers for measures of length, are the length of the simple pendulum and that of the terrestrial circumference. The adoption of the length of a simple pendulum as a unit has been objected, to because it is founded upon two heterogeneous principles, gravity and time. But if the pendulum produces the only unequivocal standard 'that can be obtained, this latter consideration preponderates. Because the length of the pendulum would be influenced by different numbers of vibrations in equal times and by different latitudes, the length of that simple pendulum may be chosen which at the equator vibrates 100000 seconds in a day, being the least arbitrary number. Yet even this length would lose the advantage of uniting with the divisions of a great circle on the globe, an advantage so important to the navigator. The simple pendulum, whose vibrations are seconds, or decimal parts of a minute, may be called the decimal pendulum: As decimal parts of a minute are its least arbitrary division, its aliquot parts are the next less so. A simple pendulum, whose vibrations are aliquot parts of a minute, may be called an aliquot pendulum. Of all the measures of length, the most important to man is the circumference of the globe which he inhabits. The decimal division of the quadrant has been accordingly applied to the distance of the pole from the equator. Of these decimal measures, the greatest portable one has been adopted as a standard, which has been denominated the metre. But because this length may not be determined with sufficient precision, and the length of a simple pendulum may be less equivocal, that aliquot pendulum, whose equatorial length approaches nearest to it, may be chosen. The pendulum fulfilling this condition, may be called the metrical pendulum. This makes 86 vibrations in a minute, or 86000 in a day. Hence the unit of measures of length would = the length of that simple pendulum which, at the equator, makes 86 vibrations in a decimal minute ; being the nearest entire number of vibrations to cause it to approximate a decimal part of the distance of the pole from the equator. The above length, which may be called the ell, or British metre, when reduced to the level of the sea, to a vacuum, and to the temperature of melting ice, = abuut 9997997 of the French metre, = about 39.3748, or 39% nearly, English inches ; the French metre being supposed = 39.38272. It has been proposed to take for a standard the length of that simple pendulum, which at the equator makes 86400 vibrations in a day, at a certain height above the level of the sea, and at a certain temperature. An argument should be shown why this number, which is founded upon an arbitrary division of time, is to be preferred to any other number. If 0 degrees of latitude be chosen, it seems but following the same system, to choose O measures in height and o degrees of temperature. The number 86000, which is the daily number of vibrations made by the metrical pendulum, is less-arbitrary than 86400, and the length of the pendulum approaches nearer to the length of the French metre determined by actual measurement, the difference between it and the French metre being only about gobo of the latter. The equatorial length of an aliquot pendulum making 1 vibration more or less than 86 in a decimal minute, would amount to more than the error of 1English statute mile upon a nonagesimal degree, which has been estimated at between 69 and 69 of these miles. Consequently such a pendulum cannot be metrical. From the proposed ell, or British metre, may be derived the following tables, which would be equally suitable to the French metrical system, should the latter be preferred. Universal Long Measure. 100 stadiums=1 league, 10 of which may be estimated=1 mean grade of latitude, or hundredth part of the distance of the pole from the equator. Upon the above table as a foundation may be erected, by a slight alteration, that of British Long Measure. By diminishing the inch by about to and the pole by about 11 inch, the British table of Long Measure would then be as follows: 10 digits=4 inches=1 hand. 30 digits=12 inches=1 foot. 90 digits=3 inches=1 yard. 100 digits=40 inches=i ell. 5 ells=200 inches=1 pole. 100 ells=20 poles=1 stadium. 2 stadiums=40 poles=1 furlong. 16 stadiums=8 furlongs=1 mile. This table possesses the advantage of uniting the English portable and itinerary measures of length, namely, the subdivisions of the yard and mile. At present the link of a chain=74 inches. According to the plan proposed, 1 furlong=1000 links=8000 inches., 1 link=8 inches. Thus by a slight alteration of the inch and pole, the British measures of length might assume universality, by consisting of multiples of reputed decimal parts of the terrestrial quadrant. Universal Square Measure. ells=1 are. 100 ares=1 square stadium, &c. Upon this and the proposed table of British Long Measure may be founded that of British Square Measure. 100 square Universal Cubic Measure. 1,000,000 cubic digits=1 cubic ell, &c. British Cubic Measure. 1000 cub. digits=64 cub. inches=1 cub. hand. 27,000 cub. digits=27 cub. kands=1 cub.foot. 1000 cub. hands=64,000 cub. inches=1 cub. ell. Universal Measure of Capacity. The cube of 10 digits may be considered as the unit of measures of capacity, which may be called the quart and = about 61•0457, or 61% nearly of the present cubic inches. 100 jills=1 quart. 100 quarts=1 hectolitre, &c. As the proposed quart or cubic hand is between the present wine and ale quart, it may be considered as the foundation of VOL. XVI. Рат. O British Measure of Capacity: By assuming 40 of these quarts=1 bushel, which would then be between the present corn and coal bushels, and increasing the beer hogshead by about a pint, the table would be as follows: 50 jills=1 pint. 4 quarts=1 gallon. 25 bushels=2 bults=1 load, or cub. ell. If the firkin were made the proposed bushel, it would then be between the present ale and beer firkins. If the gallon were derived from the proposed bushel in the usual manner, the table would proceed thus : 5 quarts=1 gallon. Universal Weights. 100 centigrammes=1 gramme. 100 todds=1 ton. British Weights. By assuming 400 grammes= 1 pound, this pound, would about 6173 troy grains, which would then be between the present troy and avoirdupois pounds. Then by diminishing the troy grain by about 16, the table would be as follows : 16 grains=1 gramme. 400 grains=25 grammes=1 ounce. 4 quarterns=16 ounces=1 pound. 4 todds=100 pounds=1 hundred wt. 100 todds=25 hundred wts.=1 ton. If the names gramme and dram be thought too much alike in sound, the latter may be omitted, or the former may be fresh named, If the proposed hundred weight be objected to, 5 todds may be assumed=1 quintal, 20 of which would=the proposed ton. This quintal would not be 2 avoirdupois pounds less than the present hundred weight. Indeed it may perhaps be better to avoid the name of hundred in weight to prevent its being confounded with that of hundred in numeration. The apothecaries' weights might remain the same; the apothecaries' grain being about 10 % of the proposed grain. But as it would be more simple to have but one system of weights, even the apothecaries' weights, if thought proper, may be very gradually destroyed, by first taking away the pound and computing by tens, hundreds, &c. of ounces; afterwards, taking away very gradually, one by one, the ounce, dram, and scruple in the same manner, leaving only the grain, which might be ultimately exchanged for one built upon a universal basis. Universal Coins. The weight of 10 grammes in copper may be considered as the unit of coins, which may be called the cent, 100 cents=1 dollar in silver). Alloy of metals=ito. If the present halfpenny might pass for the proposed cent, and the present shilling for 25 cents, the table of British Coins Might be as follows: 2 farthings=1 cent. q cents=1 penny. 5 dollars=1 pound, or sovereign. 'The increase of i halfpenny upon a shilling would not be so great an alteration as the old dollars underwent, namely, from 5 shillings to 58. 6d. |