Intelligence and Miscellaneous Articles. 545 



Owing to indisposition, I have been obliged to leave my experi- 

 ments for the present incomplete. But I am desirous, before the 

 session of the Royal Society closes, to place on record some facts 

 which I have observed, and also some conclusions which I deduce 

 from these and other recent experiments and discussions. 



Mr. Faraday's chief fact, to which the term " regelation " has 

 been more lately applied, is this, that pieces of ice, in a medium 

 above 32°, when closely applied, freeze together ; and flannel adheres 

 apparently by congealing to ice under the same circumstances. 



1. These observations I have confirmed. But I have also found 

 that metals become frozen to ice when they are surrounded by it, or 

 when they are otherwise prevented from transmitting heat too 

 abundantly. Thus, a pile of shillings being laid on a piece of ice in 

 a warm room, the lowest shilling, after becoming sunk in the ice, was 

 found firmly attached to it. 



2. Mere contact, without pressure, is sufficient to produce these 

 effects. Two slabs of ice, having their corresponding surfaces ground 

 tolerably flat, were suspended in an inhabited room upon a horizontal 

 glass rod passing through two holes in the plates of ice, so that the 

 plane of the plates was vertical. Contact of the even surfaces was 

 obtained by means of two very weak pieces of watch-spring. In an 

 hour and a half the cohesion was so complete, that, when violently 

 broken in pieces, many portions of the plates (which had each a 

 surface of twenty or more square inches) continued united. In fact, 

 it appeared as complete as in another experiment where similar sur- 

 faces were pressed together by weights. I conclude that the eff^ect 

 of pressure in assisting " regelation," is principally or solely due to 

 the larger surfaces of contact obtained by the moulding of the 

 surfaces to one another. 



3. Masses of strong ice, which had already for a long time been 

 floating in unfrozen water-casks, or kept for days in a thawing state, 

 being rapidly pounded, showed a temperature 0°'3 Fahrenheit below 

 the true freezing-point, indicated by delicate thermometers (both of 

 mercury and alcohol), carefully tested by long immersions in a con- 

 siderable mass of pounded ice or snow in a thawing state. 



4. Water being carefully frozen into a cylinder several inches 

 long, with the bulb of a thermometer in its axis, and the cylinder 

 being then gradually thawed, or allowed to lie for a considerable 

 time in pounded ice at a thawing temperature, showed also a tempe- 

 rature decidedly inferior to 32°, not less, I think, than 0°'35 Fahr. 



I think that the preceding results are all explicable on the one 

 admission, that Person's view of the gradual liquefaction of ice is 

 correct {Comples Rendus, 1850, vol. xxx. p. 526*), or that ice gra- 

 dually absorbs latent heat from a point very sensibly lower than the 

 zero of the Centigrade scale. 



I. This explains the j)ermanent lower temperature of the interior 

 of ice. 



Let AB be the surface of a block of ice contained in water at 

 what is called a freezing temperature. That temperature is marked 

 by the level of the line QP above some arbitrary zero. LM is, in 

 • Quoted by me in 1851, in my sixteenth letter on Glaciers. 

 I'ltil. Mag. S. 4. No. 1 10. Suppl. Vol. IG. 2 N 



