82 Canadian Record of Science. 



as3 l 7. l 75° F. The probability is that there are strong bottom 

 currents which prevent what would be the natural course 

 upwards of the colder and lighter waters of the bottom. 

 Commander Boulton is also inclined to take this view. The 

 two leading physical features which characterize the bottom 

 of the bay, are, first, the somewhat shelving nature of the 

 bottom from east to west, the western side, along nearly its 

 whole length, being remarkably deep, and continuing so up 

 to the very cliffs which bound it, and, secondly, the appa- 

 rently complete severance of its deeper waters from those of 

 Lake Huron by the submerged escarpment between the 

 Bruce peninsula and the Manitoulin Islands. These two 

 features may be found to have some influence in this con- 

 nection. 



Harbour Temperatures. 



The more land-locked a harbour is, the higher is the 

 temperature of its water as compared with that of t\ie water 

 outside of the harbour. It may be equally predicated that, 

 up to a certain point, the more foul the harbour water is, 

 the higher, to a further extent, is the temperature likely to 

 be. At Kingston, this occasionally, in midsummer, is well 

 illustrated. On 10th July last, after two or three days of 

 comparatively calm weather, during which the upturned 

 sediment of the bottom, the floating harbour accumulations, 

 surface drainage, and the sewage appeared to be gathered 

 together in the harbour to an unusual extent, while the 

 mercury at 3000 feet off the wharves indicated 73.5° F. two 

 inches under the surface ; it, at 100 feet, rose to 78° F., at 

 the same depth three hours subsequently, though in the 

 meantime the sky had become overcast with clouds. These 

 accumulations contaminate the water for very considerable 

 distances outward in the harbour, and warn us how impor- 

 tant to the health of cities and towns, similarly situated, it 

 is to have the water, supplied for domestic uses, taken from 

 points beyond any possible line to which such accumula- 

 tions may extend. The higher temperature of the harbour 



