Intelligence and Miscellaneous Articles, 243 



would not favour the occurrence of freezing of new ice there rather 

 than at the top, but that, on the contrary, if effects on the tendency 

 to crystallization are to be sought for in such a slight cause, it should 

 rather be taken that the greater fluid friction at the bottom, and the 

 heavier pressure there, are causes slightly, but certainly very slightly, 

 tending to oppose the freezing of new ice at the bottom. 



Mr. Hodges, the engineer of the contractors for the great bridge 

 across the St. Lawrence at Montreal, in his large and valuable work 

 recently published (in 1860) on the construction of that bridge, de- 

 scribes the ice-phenomena of the St. Lawrence, which he had been 

 obliged during many years to watch and inquire into with anxious 

 care ; and in respect to the origin of the ground-ice, he supposes 

 that the water in passing down rapids may become aerated by the 

 rapidity of the current, and that particles or globules of cold air, 

 being whirled by the eddies till they come in contact with the 

 rocky bed of the river, attach themselves to it, and there give out 

 cold which they have brought with them from the very cold atmo- 

 sphere above, and so induce the freezing of ice around them- 

 selves in adhesion to the bottom of the river. As against this spe- 

 culation, the author of the present paper states that the cold which 

 could be conveyed down into the water by small bubbles would 

 be totally inadequate to produce the results in question, and that 

 any freezing which small bubbles of air could produce would occur 

 during the period of their eddying about through the water, rather 

 than at a later time, when their temperature would be assimilated to 

 that of the water. The author's view, which it was the chief object 

 of the paper to present, is that crystals or small pieces of ice are 

 frozen from the water at any part of the depth of the stream, whether 

 the top, the middle, or the bottom, where cold may be introduced 

 either by contact or radiation, and that they may be supplied in part 

 by snow or otherwise ; and that they are whirled about in currents 

 and eddies until they come in contact with any fixed objects to which 

 they can adhere, and which may perhaps be rocks or stones, or may 

 be pieces of ice accidentally caught in crevices of the rocks or stones, 

 or may be ground-ice already grown from such a beginning. The 

 growth of the ice by adhesion of new particles formed elsewhere he 

 attributes to the property of any two pieces of moist ice to adhere when 

 brought into contact, which has been a subject of much discussion of 

 late years, and of which the author's views are to be found in various 

 recent papers in the ' Proceedings of the Royal Society/ and have 

 also been submitted from time to time to the Belfast Natural History 

 and Philosophical Society. He is confident that the anchor ice is not 

 formed by crystallization at the place where it is found adhering. 

 He is aware that the idea has sometimes been mooted, that snow falling 

 into rivers might somehow be converted into anchor ice ; but he is 

 not aware that hitherto any explanation has been offered coupling the 

 formation of the anchor ice with the property of ice now commonly 

 designated as " regelation," but which until late years was not very 

 generally known or understood, more especially as a property capable 

 of bringing about the union of small pieces of ice floating freely under 



