46 
Such an opportunity was given by the introduction of 
self-registering instruments, and, as far as I know, Mr. 
Chambers stands alone in finding the values of his photo- 
graphic curves for a time of his own convenience. He has 
given up Gottingen time, but he has still further departed 
from the hours of local time by giving the readings for his 
three instruments, at seventeen, eighteen, and nineteen 
minutes past each hour. Nobody can object if Mr. 
Chambers takes any hour he pleases for his reductions, but 
Mr. Chambers, on the other hand, cannot object if others 
feel irritated at the additional labour which is thereby im- 
posed on them. 
I do not enter into the general question whether it is 
advisable or not to analyse the diurnal variation in the only 
way in which it can be analysed ; because the question has 
gone beyond the stage of discussion. The calculations are 
going to be made, and the result only can show whether I 
was justified in bringing the matter before the notice of the 
Magnetical Committee of the British Association. 
