1833.] Means of making Ice by the Natives of Bengal. 85 
siderable weight, which was owing to the absorption of moisture on 
the surface of the water exceeding the loss by evaporation from the 
external surface. The quantity of cold water which is sprinkled over 
the dishes is not sufficiently large to explain the great increase in the 
weight of the dishes, which I found was about the same when no water 
had been thrown over the bed. Glazed vessels of different colours 
were placed amongst the unglazed, which in the morning were found 
to have thicker ice, and to have gained more weight than the common 
dishes. 
In eight experiments with the common unglazed ice-dishes, the aver- 
age gain in weight, was 68.5 grains; and of five experiments with 
smaller black-glazed slightly porous dishes, this average was 110 
grains. As the surrounding media must have a great influence on the 
formation of ice, I noted their different temperatures. The air at the 
ice-fields was always found warmer in the evening, and much colder 
in the morning, than at the neighbouring village of Bandel, where the 
ground is more sheltered by trees, from the direct influence of the 
sun’s rays. The average of a number of experiments in favourable 
weather for making ice, gives, at Bandel, 70 degrees in the evening, 
and 56 in the morning; and at the ice-fields 72° in the evening, 
and 46° in the morning. 
The temperature of the different substances in the neighbourhood, or 
forming part of the ice-beds, was examined a little before sun-set and 
soon after sun-rise: on a clear evening and favourable morning, they 
were found to be as follows:— 
Morning. Evening. 
The air 5 feet above the ice-beds, ...... ........ 49° to 46°: 72° 
Water in the large jars between the ice-beds,...... 44 to 60 68 
Water in a deep tank in ice-fields,................ 57 77 
Ground in the neighbourhood, immediately under 
202 ALLS A ME Pn oe Se 54 57 
Straw in the ice-beds, 3 or 4 inches under the surface, 42 to 46 48 
Ditto, of a thatched hut in the ice-fields, obliquely 
Sumosed tothe sky,.... 0.0.00 cs eees sere ewee sess 44 61 
The temperature that generally prevails on nights fitted for the — 
manufacture may be learned from the following table, for which I am 
chiefly indebted to Mr. Herklots, Fiscal of Chinsurah. 
