130 A curfory Vkzu of fome of the 



and to attain, refpe6ling the figure of the earth, a more per- 

 fctil theory than any yet given. This confirms the opinion 

 before entertained, that the figure of the earth is not a re- 

 gular curve. It refults from thefe calculations, that the flat- 

 ncfs of the earth is a 334th part; that is to lav, the axis is 

 to a diameter at the equator as 333 to 334. 



The length of the pendulum is another mean given by 

 Nature for obtaining conllaut meafures, bccaulc it is a con- 

 fequence of gravity which cannot vary. It has been efti- 

 inated for a pendulum, vibrating feconds at Paris, to be 

 -iVot'.^b V5 "f the module, or -rVoVoVo of t'^f uiclre. 



The length of the metre being deterniLucd, fcrves to lix 

 the weights and meafures of capacity. Diftllled water was 

 aflinr.ed as the body which could be moft cafily procured in 

 full purity; and Lefevre Gineau endeavoured to afcertain 

 the weioht of a kiloQ-ramme of this water taken at that tcm- 

 perature at which it has mod dcnfity. The real kilogramme, 

 the weight of a cubic decimetre of diftilled water, taken at 

 its maxinnim of denfity, and weiglied in vacuo, or the unity of 

 the weights, is 18837, °^ 2 pounds 5 gros 35 0T5 grains; 

 that is, a little more than the Paris pint, which wa^ fuppofed 

 to weigh two pounds. According to thefe experiments, the 

 cubic toot of diftilled water, taken at its maximum of den- 

 lity, is 70 pounds 223 grains. It is 70 pounds 141 graina 

 if we take the water at the temperature of -j'-q of a degree; 

 and it would be 70 pounds 130 grains, if we (liould take the 

 water at the temperature of n)elting ice. The maximum of 

 the deality of water, and therefore of its weight, is, when 

 its temperature is at about 4 degrees. The kilogramme 

 con'ams a thoufand grammes, confequently the gramme is 

 18 ,V,>, grams. 



90th Comet. The nucleus of the comet, difcovered by 

 Mechain at the obfervatory of Paris about two o'clock ia 

 the morning on the 2©th of Thermidor (Augufli 7th), be- 

 tween Gemini and the Lynx, was exceedingly fmall, was. 

 furrounded by a light ncbulofity, and had no traces of a 

 tail. The diameter of the whole was only about a minute. 

 It rofc towards the north to about 60 degrees of declination*. 

 Ttie eleriiems of its orbit were as follows : — Longitude of the 

 y defccnding 



