300 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1798. 



VII. 



Abstract of a Register of the Barometer, Thermometer, and Rain, at 

 Lyndon, in Rutland, for 1796. By Thes. Barker, Esq. p. 130. 



VIII. Of some Endeavours to Ascertain a Standard of Weight and Measure. By 

 Sir G. Shuckburgh Evelyn, Bart. F.R.S. and A. S. p. 133. 



Having for some years turned my thoughts to the consideration of an invariable 

 and imperishable standard of weight and measure, as a thing, in a philosophical 

 view, highly desirable, and likely to become extremely beneficial to the public, I 

 had, so early as 1780, taken up the idea of a universal measure, whence all the 

 rest might be derived, by means of a pendulum with a moveable centre of suspen- 

 sion, capable of such adjustments, as to be made to vibrate any number of times in 

 a given interval ; and, by comparison of the difference of the vibrations with the 

 difference of the lengths of the pendulum, which difference alone might be the 

 standard measure, to determine its positive length, if that should be thought pre- 

 ferable, under any given circumstances ; by which means, all the difficulties arising 

 in determining the actual centre of motion and of oscillation, which have hitherto 

 so much embarrassed these experiments, would be obviated. 



I made several computations of the probable accuracy that might be expected from 



