238 



Nachrichten von der Georg-Augusts Universitat und der Kbnigl. 

 Gesellschaft der Wissenschaften zu Gottingen. 1852. 12mo. 

 — From the Society. 



Monday, 17th April 1854. 



Right Rev. BISHOP TERROT, Vice-President, in the 

 Chair. 



The following Communications were read : — 



1. On the Products of Destructive Distillation of Animal 



Substances. Part. III. By Dr Thomas Anderson. 



2. Notice of the Completion of the Time-Ball Apparatus. 



By Professor C. Piazzi Smyth. 



The electric time-ball, erected on the Calton Hill last October by 

 the Government, and placed under the author's charge, has now been 

 at woi'k for five months. But the work has necessarily been of an 

 experimental or tentative character ; for before the accuracy of the 

 signals could be guaranteed, it was necessary to have experience of 

 the machinery in all weathers ; and, moreover, the present strength 

 of the Observatory establishment, and the nature of pre-existing 

 occupations, prevented the experiments being made every day. 



There have, however, been now upwards of 100 daily signals 

 made, four only of which have proved defective, and from causes 

 which have since been remedied, so that there is now strong warrant 

 against future accidents. 



In the course of the trial, the following questions presented them- 

 selves, and, if not answered satisfactorily by the experiments, suit- 

 able alterations were made in the machinery. 



1st, Is the fall of the ball equally quick in windy as in calm 

 weather \ 



The answer is, that it is so, owing to the great weight of the ball, 

 something near a ton, overpowering any side pressure of the wind, 

 while all other friction is carefully relieved. 



