CONTENTS. xm 



in. Defcription of anew Efcapement for Clocks. By Mr. Simon Goodrich p. 342 

 Efcapetnent confifting of a crank upon the arbor of the laft wheel of the train. Its advantages. 



IV. Defcription of the Furnace of Pi ofcffor Pott - - P- 344 



V. Procefs ufed to feparate the Mucilage from Linfeed Oil ; Methods of dif- 

 folving Copal for Varnifh, &c. By Mr. Timothy Sheldrake - p. 345 



VI. Analyfis of the Spinel. By Profeflbr Klaproth . - p. 349. 



VII. Verbal Procefs of the Converfion of Soft Iron into Caft Steel, by means of 

 the Diamond. By Cit. Guyton _ _ _ P- 35° 



Examination of the elaftic produfls in the eommon procefs of cementation for making fleel. Pro" 

 cefs with the diamond. A cavity was bored in a block of foft iron, and a ftopper fitted of the- 

 fame material. Into this cavity was put a diamond, with fome filings of the iron to fill the 

 remaining fpace, after which the ftopper was driven in. In this ftate (the diamond weighing 

 almoft one fixteenth part of the mafs) the whole was put into a crucible, and this placed in an- 

 other ; and the fpace between the two crucibles filled with pure filiceous fand. The external 

 crucible was well clofed and luted, and the whole expofed to the ftrong ignition of a blaft fur- 

 nace, by which the metal was fufed completely i the diamond difappeared, and the compound wa» 

 found to be fteel. 



VIII. Notice of the Experiments made by order of the Minifter of the Interior 

 of France, relative to the Finenefs of Tin or Pewter - p. 356 



The method recommended is to examine the fpecific gravity. It is lefs in compounds of lead and titt ' 

 that would be deduced by computation. Experimental refults. 



IX. A Chemical Examination of the Bath Waters. By G. S. Gibbes, B.M. 

 F.R.S. - - - - - p. 359 



X. Confl:ru<5lion of a Lamp for burning Tallow. By Mr. William Clofc p. 363 



XI. Report made to the Inftitute of Sciences and Arts (at Paris), on the 29. 

 Prairial, in the Seventh Year (June 17, i799)> in the Name of the Clafs of 

 Phyficai and Mathematical Sciences, on the ?4eafure of the Meridian of 

 France, and the Refults which have been deduced to determine the new 

 Metrical Syfbem. (Concluded from page 324) - P- 3^5 



Method by which the unity of weight was deduced from the metre. A hollow cylinder of braf« 

 was conftrufted, and its dimenfions afcertained by meafuring 37 different lines of length, and 

 48 different diameters. It was weighed in air and in water at known temperatures, and from ths 

 difference of the weight duly correded, the cubic decimetre of water, or true kilogramme, was 

 found. The ratio between this weight and the marc of the pile of Charlemagne was alfo fettled. 

 Standards of the metre, and the kilogramme in platina, in iron, and in brafs. Length of the fimple 

 pendulum for feconds at Paris. 



XII. On the Web of the Garden-Spider. By a Correfpondent -• p.. 369 

 Adhefive quality of the polygonal threads of the fpider's web. Obfervationi. 



XIII.. Plan of Experiments which were made in the Garden of Plants p. 370 



On. 



