in Fluids, 289 



was melted in the very beginning of the experiments, or 

 while the hot water was actually -pouring into the jar, 

 which operation commonly lasted about one minute ; and 

 the irregularities in the results of the experiments, and 

 particularly of the three first, showed evidently that the- 

 quantity of ice melted in that operation was different in 

 different experiments. I had indeed foreseen that this 

 would be the case, and on that account it was that I cov- 

 ered the surface of the ice with a circular piece of strong 

 paper, and always took care to pour the water very 

 gently into the jar; but I found that all these precau- 

 tions were not sufficient to prevent very considerable 

 anomalies in the results of the experiments; and as I 

 found reason to suspect that the motion in the mass of 

 the hat water, which was unavoidably occasioned by re- 

 moving the circular piece of paper which covered the ice, 

 was the principal cause of these inaccuracies, I had re- 

 course to another and a better contrivance. 



Having procured a flat, shallow dish, of light wood, 

 half an inch deep, 4|- inches in diameter (or something 

 less than the internal diameter of the jar), and about \ 

 of an inch thick at its bottom, I bored a great number 

 of very small holes through its bottom, which gave it 

 the appearance of a sieve. This perforated wooden dish, 

 having been previously made ice-cold^ was placed on the 

 surface of the ice in the jar, and the hot water being 

 gently poured into the dish through a long wooden tube, 

 as this perforated dish floated and remained constantly 

 at the surface of the water, and as the water passing 

 t^hrough such a great number (many hundreds) of small 

 holes was not projected downwards with force, it is evi- 

 dent that by this simple contrivance those violent motions 

 in the mass of water in the jar which before took place 



VOL. I. 19 



