ESTIMATION OF SMALL EXCESSES OF WEIGHT. 



29 



Time of Vibration at end. 



^1 



Observed time of 



passage of pointer 



through resting- 



point. 



> 



Observed time of 



passage of pointer 



through resting- 



point. 



Time of 10 

 vibrations. 



o 



2 



4 

 6 



Pointer apparen 



h. m. s. 

 II 26 19 

 II 26 44-5 

 II 27 10 

 II 27 35-5 



Mp-ftn vnhie of in 



tly moving from left to right. 



h. m. B. 

 10 1 1 28 27 

 12 II 28 53 

 14 II 29 18 

 16 II 29 44 



vihrat-.inns 



s. 



128 

 128 5 

 128 

 1285 



128-25 







1 

 3 

 5 

 7 



Pointer apparen 



11 26 32*5 

 11 26 58 

 II 27 23-5 

 II 27 49 



lVf(>fl.Tl ValllO of T0 1 



tly moving 



II 

 13 



17 



from right to left. 



II 28 39 

 II 29 5 

 II 29 30-5 

 II 29 56-5 



126-5 



127 

 127 

 127-5 



ribrations 





127 









Mean of means =i27'625; /j, = 12^7625. 



Remembering that one tenth of a division of the scale 

 is an angle of •0003996° in circular measure^ formula (4), 

 expressed in milligrammes^ becomes 



^ = ^,o-3996^(M^r + 2Pa^). 



In our present example^ 



^ = 35-83, 



/ = ^-4^^= 12-725, 



* For this, as for several other cases, I removed the pans and hung the 

 weights directly by fine wires from the suspending-pieces. By this means 

 the resistance of the air was very much diminished. 



