CONTINUOUS ELECTRIC CALORIMETRY. 
59 
meeting of the British Association, in 1897, but it was at that time incomplete in 
certain important details, and only three sets of observations, at 5°, 25°, and 45°, 
were obtained. At the commencement of the next session I secured the services of 
Mr. Stovel, the most promising of the electrical students of the previous session, to 
assist Mr. Barnes in setting up the apparatus and taking the observations. I spent 
a good deal of my leisure at this time in the adaptation of the method to the 
determination of the specific heat of steam, but continued to give the closest personal 
supervision to the work on the specific heat of water, and made several tests of the 
apparatus in the vacations when I had more leisure. A great part of the work 
during this session consisted in perfecting the mechanical details of the apparatus, 
which is always a most important and laborious process in an investigation of this 
character. The last work in which I personally assisted before leaving Montreal 
was the drawing and annealing of the platinum-silver wire for the Mica Current- 
Standards referred to in Section 7. By this time the fundamental portions of 
the apparatus had been practically perfected, but the observations, though very 
numerous, did not extend beyond the range 0° to 55°, and they had for the most 
part been taken for the purpose of testing improvements which from time to time 
were introduced, and could not be regarded as parts of a regular series. 
When I left Montreal about the end of May, 1898, it was arranged that Mr. Barnes 
should continue the experiments throughout the summer, and should follow me to 
England with the apparatus as soon as I could make preparations for carrying on the 
work in my new T laboratory. Unfortunately this plan proved to be impracticable, 
which caused some delay in the work, as I was unable to render him any material 
assistance by correspondence at such a distance, owing to the impossibility of 
detecting sources of error in any particular case without seeing the apparatus or the 
observations. But by the end of the McGill College session in April 1899, he had 
succeeded so well in overcoming his difficulties, and the work appeared to be 
progressing so favourably, that it seemed inadvisable to disturb the apparatus. I 
therefore reluctantly consented to abandon any further share in the observations. 
It had originally been intended that 1 should write the paper describing the theory 
and results of the investigation; but as, in the end, Mr. Barnes was solely 
responsible for the final series of observations, it seemed more appropriate that he 
should write the account of that part of the work. 
The primary object of my own contribution is to supplement his account of the 
final observations by a general discussion of the theory of the experiment, and a 
description of the difficulties encountered in the earlier stages. He was unable to 
speak with authority on these points, as a good deal of this work was done before he 
joined the investigation, and I had not thought it necessary to give him a detailed 
account of it, since it was originally intended that we should finish the work 
together. A similar partition of authorship has already been sanctioned in a similar 
case in the work of Beynolds and Moorby, and possesses undoubted advantages in 
