268 



Mr. A. M. Worthington on the 



[June 15_, 



When the tliickening does not keep pace with the lengthening of the 

 cylinder, drops will split off. That in such case the arms split at the 

 ends rather than in the middle is, I think, to be attributed to the fact 

 that the thickening spreads from the centre to the ends, which receive 

 their additional liquid later. 



Set 8. 



It is perhaps worthy of remark that the earliest stage I was able to 

 see was nearly the maximum spread for every height of fall, for both 

 milk and mercury. As my adjustment for seeing the first stage was 

 nearly the same in all cases, I have reason to assume that the time which 

 elapsed between the contact of the drop and the appearance of the spark 

 was nearly the same. Hence the conclusion that the drop requires the 

 same time to reach its maximum spread whatever the diameter of the 

 spread ; or, in other words, the oscillation follows the law of a simple 

 elastic force. The limits of error are, however, here wide. 



The difficulty of counting the arms was considerable. Most frequently 

 there were 6, sometimes 8 or 12, sometimes more ; and I am inclined to 

 think their number was always even. 



The number of the drops left from the first spreading out in the case 

 of higher falls was hard to count. In the case of mercury on unsmoked 

 glass, these were left on the plate in a more or less complete circle ; and 



