16 ROYAL SOCIETY OF CANADA 



evtn by so great u project as the Chicago Sanitary Canal, probably the 

 most important piece of engineering Avork at present under constniction. 



Its real object is to relieve the city of Chicago and the contiguous ter- 

 ritory of sewage, though it is also to be used as a ship canal. To give an 

 idea of the magnitude of its conception. I may state that its section is 

 greater than that of either the Manchester, the Suez, or the North Sea 

 shij) canals. The depth of the Avater is to vary from a minimum of 22 

 feet to a maximum of 26 feet. The canal will be thirty-five miles in 

 length, will be formed by the excavation of nearly forty million cubic 

 yards of material, and will cost from twentj^-seven to twenty-eight millions 

 of dollars. 



River improvements and hj'draulic schemes of all kinds involve prob- 

 lems of great ditïiculty, which can only be solved by long experience 

 and observation, and by intricate and delicate experiments. Professor 

 Osborne Reynolds, at the meeting of the British Association in 1887, pre- 

 sented an important report, in which he showed that it is possible by 

 means of experiments on a small scale to deduce certain laws relating to 

 the régime of rivers and estuaries which " seem to afford a ready means 

 of investigating and determining beforehand the effects of any proposed 

 estuary or harbour works.' Before allowing the construction of piers 

 and dykes, would it not be well to require that preliminary experiments 

 should be carried out, on the lines indicated by Reynolds, as to what 

 would be the certain result of such works upon the water-way —especially 

 when we consider the enormous interests often involved ? 



A serious source of difficulty in our northern rivers is the presence of 

 frazil and anchor ice during the winter. It seems strange that no sys- 

 tematic attempt has hitherto been made to investigate the conditions 

 under which it is produced, or to find out whether any means could be 

 adopted of preventing its formation in the neighbourhood of machinery 

 driven by water power. With this object in view, during the months of 

 February and March, Mr. H. T. Barnes, M.A.Sc, made a preliminary 

 series of observations with a Callendar electrical thermometer to deter- 

 mine the variations in temperature of the water of the St. Lawrence, and 

 the results are fully described in a paper which will be read at the present 

 meeting. It was found that even in the most severe weather the tem- 

 perature of the water did not fall more than the one-hundredth of a 

 degree below 32° Fahrenheit. Thus the formation of frazil is ai>parently 

 not due to a lowering of the temperature but to radiation. 



In connection with the subject of hydraulics, I may state that in 

 1894 and 1895 a lengthy series of experiments was carried out by myself 

 with a view to determine with greater accuracy and wider scope than 

 had hitherto been done the co-efficients of discharge for jets flowing 

 through orifices of various forms. 



These results have now been published, but certain sources of error 



