262 ANNUAL OF SCIENTIFIC DISCOVERY. 



perature at this time ranged from 47 Fall, to 57 Fah. The lowest 

 depth reached, in this shaft, was, as before stated, thirty-four feet ; 

 and the men before leaving tried to drive an iron bar through the 

 frozen ground at the bottom, but without success, the earth being 

 too solid. 



In concluding the report of their investigations, the committee say : 

 Although we do not feel that we have been able to remove all doubts 

 as to the true theory of the phenomena of the frozen well, still we 

 incline to believe that the freezing is due to the nature of the con- 

 ducting medium in which the well exists, and that the wave of heat 

 in the summer months is not adequate to overcome the cold of the 

 longer cold months, while the uncommonly severe winters of 1856 

 and 1857 may have lowered the temperature of the rocky masses of 

 boulders, so that the wave of summer heat has not yet been able to 

 reach the frozen mass, which, once congealed, would resist thawing 

 on account of the slow conduction of ice. It should also be remem- 

 bered that water does not conduct heat downward readily, though 

 it does upward by convection. 1 



The existence of beds of boulders in other cold and frozen wells, 

 as in one at Tioga, N. Y., seems to point to the same solution. 



The ice in the Brandon well forms some time in November, and it 

 remains until September, thus showing only a brief period when the 

 temperature of the bottom of the well is above the freezing temper- 

 ature, while the great mass of boulders remains much below it; the 

 well, being more exposed, receives the first warmth by conduction of 

 its walls exposed to the air. 



Among the hypotheses which have been offered to account for the 

 phenomena of the frozen wells, are the following : 



1. The penetration of cold currents of air through the boulder 

 stratum. This hypothesis is without any foundation, because there 

 are no open spaces, and the boulders are closely cemented together 

 by being imbedded in clay and sand ; and also because the fact is 

 ascertained that there are no currents of air moving in the mass, or 

 in the well, the flame of a candle placed near the stony walls not 

 being in the least deflected. 



2. The descent of cold air into the well, in mid-winter, communi- 

 cating the degree of cold to the walls of the well. This conjecture 

 is insufficient, since the ice existed before the well was sunk, and 

 when there was no opening for the air to descend into. This fact 

 was not only ascertained at the time the well was sunk, as witnessed 

 by credible persons residing in the vicinity, but has also been fully 

 verified by sinking a shaft into the boulder bed by this committee, 

 and by the discovery of an extensive frozen stratum in October. 



3. Radiations from the bottom of the well. If this conjecture was 



1 The familiar experiment of boiling water upon the surface of a cake of ice 

 without melting' it, and that of boiling water at its surface, by means of a plate 

 of hot iron, placed over it, while the water below is not heated, illustrates this 

 statement. 



It is true that the maximum density of water is at 39 Fah., and that it sinks 

 when at this temperature iu water that is cither warmer or colder, but this move- 

 ment is limited to a few degrees of temperature. Ice, having its particles fixed, 

 does not allow of the varying of heat by convection, as it is called, and is a very 

 bad conductor of heat, as 'is obvious to all who observe a cake of it exposed to a 

 warm atmosphere. 



