July 19, 1906] 



NA TURE 



27: 



fraction of his time should be absorbed by giving 

 lectures to elementary students. This difluult ques- 

 tion of the division of time appears to have been 

 satisfactorily solved in the Physics Building. 



The first research professor, H. L. Callendar, was 

 an active and able investigator. He invented and 

 improved his platinum thermometer with an ingeni- 

 ous compensation method, and applied it to various 

 uses. In conjunction with Prof. J. S. Nicholson, of 

 the engineering building, he solved many temperature 

 problems connected with the steam engine. He in- 

 vestigated some important meteorological questions, 

 determining the temperature at various depths in the 

 earth — a matter of special interest during the severe 

 winters in Canada. He also constructed a self-record- 



hcat of water at various temperatures. Dr. Barnes, 

 with Dr. CoUer, determined the effect of temperature 

 on stream lines and the critical velocity. He has 

 also made a close study of the properties and pecu- 

 liarities of ice formation in Canadian rivers. Freez- 

 ing does not occur merely at the surface, as in most 

 English rivers, but, after passing rapids, water may 

 congeal at the bottom and form "anchor ice." Still 

 more remarkable is the formation of " frazil," con- 

 sisting of minute crystals pervading the whole mass 

 of water. The presence of ice in this state occasions 

 serious trouble in the turbines of the power stations, 

 and special precautions are necessary to mitigate the 

 evil. 



On the appointment of Prof. Callendar to the chair 



-Prof. E. UutherfurJ, F.R.S., 



ing instrument which measured the difference of 

 temperatures between the top of Mount Royal and 

 the base near the observatory. Further results have 

 been obtained by Prof. C. H. McLeod and Dr. H. T. 

 Barnes, using the same instrument. The latter was 

 also associated with Prof. Callendar in effecting some 

 improvements in the Clark cell as a standard of 

 electromotive force. But Prof. Callendar's most im- 

 portant work at McGill was the development, in con- 

 junction with Dr. Barnes, of the continuous flow 

 method of calorimetry. This has proved a great 

 advance, both for simplicity and accuracy, on the 

 older methods of calorimetry. Very exact determin- 

 ations have thus been made by Dr. Barnes of the 

 mechanical equivalent of heat, and of the specific 



NO. I 9 16, VOL. 74] 



of physics at University College, London, Prof. Cox 

 again visited the Cavendish Laboratory, and, on the 

 advice of Prof. J. J. Thomson, he selected to fill 

 the vacancy E. Rutherford, a young man who had 

 already distinguished himself for originality, insight, 

 and great capacity for work. Soon after M. Bec- 

 querei's discovery of the radiations from uranium, 

 Rutherford had published a paper on that subject, 

 and removed some misapprehensions as to the pro- 

 perties of the radiations. Moreover, he had served 

 a most useful apprenticeship on the investigation of 

 the properties of ions, whether produced by Rontgen 

 rays, ultra-violet light, or by uranium. This thorough 

 mastery of the indispensable elements served him 

 in good stead when he continued at Montreal his 



