[ 289 ] 



M[EASURES] 



(From MS. N. 20. See Table of Contents at the beginning of this volume.} 



[These "Measures" are on a set of loose sheets of different sizes marked M. i to 

 M. 21, and another set marked M. i to M. 12.] 



581] Comparative charges of jars and battery 



* 



M. i. If jar i is electrified till straw electrometer separates to ij, and its 

 electricity is communicated to jars 2 + 4, pith electrometer separates 5j. There- 

 fore charge required to make pith balls separate 5f is to that required to make 

 straw electrometer separate i\ as 3184 to 8909, and that to make pith separate 

 5j to that to make straw separate if as 2920 to 8909. 



f 5 

 Jars i and 2 being electrified by wire and jar 1 6 by coating till pith electro- 



(-7 

 meter separated ij and a communication being then made between them in 



51 

 the manner used for trying Leyden vials, pith balls separate 5^ negative, 



5i 



5 ri3i6t 



therefore charge of jar 6 should be -j 1273 . 



7 (.1231 



Charge of 1 + 2 + 3 + 4= I2 544- 



Jars 1 + 2 + 3 + 4 being compared in the same manner with jar 



pith balls did not separate at all. 



M. 2. If the charge of jars i + 2 + 3 + 4 is called 4 



jar i or 2 is nearly = i 



5. 6, or 7 4 



I row of battery = 22 



whole battery = 154 



Jar 8 being electrified it was found that it must be touched 7^ times by 

 white cyl. to reduce the quantity of electricity to J. The 4 jars must be touched 

 8 times by do. Therefore charge of jar 8 = 3|. 



A piece of crown glass i foot square of which weighed 10-12 was coated with 

 tinfoil about 10 inches square. 



* [Art. 411.] 



f [These numbers are given as in the MS. They should be each multiplied 

 by 10. See also Art. 585, where the numbers seem to be deduced from some other 

 experiment.] 



C.P.I. 19 



