450 



Prof. Guthrie on Drops, 



[Recess, 



Hence it appears that, within the above Hmits, on the whole, the weight 

 or size of a drop diminishes as its growth-time increases. Further, it seems 

 that between the rates fft='433 and gt—'bQ7 a minimum occurs, that is, 

 instead of there being a continuous diminution in the weight as the growth- 

 time increases, there is at first a diminution, then an increase, and finally 

 a continuous diminution, so that drops of the rate ^^='500 have sensibly 

 the same size as those of the rate gt = 'Q?>2). 



In order to establish more precisely the position of this minimum and 

 the general relation between rate and size, the observations must be both 

 more minute and more extended. For this purpose a fresh sample of oil 

 was taken, and the time-intervals extended from 25" per 60 drops to 240" 

 per 20 drops ; as before, four experiments were made at each time-interval. 

 The mean results are given in Table IV. in which the values of gt are 

 obtained by dividing the time-intervals by the number of drops. The 

 mean weights of the single drops are got as in Table III. The weights of 

 oil passing in one second are found by dividing the terms of column 2 by 

 those of column 1, which correspond to them. 



Table IV. — Cocoa-nut oil (specific gravity =0*9 195). 

 T=29° C — 29°'4 C. 

 Radius of ivory sphere = 22'l millims. 



gt. 



Mean weight 



Weight of oil 



of single drop. 



passing per second. 





grm. 



grm. 



(()'333) 



(009264) 



(0-27792) 



0-417 



0-08265 



0-19837 



0-433 



0-08074 



0-18631 



0-450 



0-08185 



18189 



0-467 



0-07918 



0-16968 



0-483 



007932 



0-16412 



0-500 



0-08017 



0-16035 



0-517 



0-08017 



015518 



0-533 



0-07961 



0-14927 



0-550 



007693 



0-13985 



0-567 



0-07664 



13524 



0-583 



007558 



0-12957 



0-600 



0-07334 



12221 



0-617 



07320 



0-11871 



0-633 



0-07321 



0-11560 



0-6C7 



007260 



0-10891 



0-750 



0-07102 



009469 



0-833 



0-06902 



08283 



1-000 



0-06605 



0-06605 



1-500 



006215 



0-04144 



2-000 



0-05986 



0-02993 



3 000 



0-05710 



0-01903 



4-000 



005561 



001432 



5 000 



005469 



0-01094 



12-000 



05201 



0-00433 



* A Table exhibiting the details is given in the MS., which is preserved for reference 

 in the Archives. 



