[muri'hy] the ice question 169 



In Dr. Barnes' work, lie emphasized a point with which I was 

 familiar, i.e., that river water remains just at the freezing point all 

 winter — as illustrated in Fig. 2a. He went further than this, however. 

 He showed that water temperature variations from the freezing point 

 frequently occurred in the winter and that they ivere measurable — in 

 thousandths of one degree! His work was made possible by the aid of 

 a Callendar thermometer which will measure a temperature variation 

 of 1/10,000 of a degree with accuracy. Fig. 8rt shows the relative sizes 

 of a Callendar thermometer scale and a mercury thermometer scale. 



Dr. Barnes discovered that the water's temperature in the Lachine 

 Eapids where his work was carried out was sometimes 32.001° F., and 

 sometimes 81.999° F. ! He noticed that a change of a couple of thou- 

 sandths of a degree, from one side to the other of the freezing point, was 

 — to use his own language : " accompanied by tremendous physical 

 effects." Frazil was made in immense quantities, after dark or on a 

 cloudy day, if the change in water temperature was towards the negative 

 side of, or below, the freezing point; and anchor ice was compelled to 

 loosen its grip on the bed of the stream if the water became warmed to 

 the extent of a thousandth of a degree on the positive side of the freezing 

 point by the heat of the sun. 



The beneficial effects of preventing the cold air from chilling the 

 metal parts of hydraulic equipment had long been well-known to me, 

 and the action of the heat of the sun in relieving frozen plants before 

 any appreciable, or, as we thought, mca-sura'ble, rise in water tempera- 

 ture occurred, was also well-known for many years. No one, however, at 

 least to my knowledge, had ever conceived what delicate or almost in- 

 finitely minute Avater temperature changes actually take place in our 

 streams in winter until Dr. Barnes made this point so beautifully clear 

 when carrying out his investigations for the Montreal Harbour Commis- 

 sioners. The light shed upon my study of the Ice Question by the pub- 

 lication of Dr. Barnes' work opened up the following line of thought: 

 Energy measured in millions of horse power may be necessary to change 

 the water used in a power plant from the solid to the liquid state with- 

 out raising its temperature; hundreds of thousands of horse power may 

 be required to raise the temperature of all this water one degree; but, 

 the hydraulic power plant operator has nothing to do with either of these 

 problems. His duty is to prevent the temperature of his apparatus from 

 being lowered to the freezing point — to keep this temperature 1/10,000 

 of a degree on. the positive side of the freezing point — and when this is 

 done frazil will then have no inclination to adhere to the apparatus. 



