LIST OF SPECIMENS FORWARDED. 1st. First class glance ores and copper pyrites. 2nd. Ditto glance ores, sometimes pounded and sold as Soorma (antimony) for the eyes. 3rd. Average copper ores, usually smelted. 4th.-Specimen of strata in which the copper ores occur. 5th.-Average copper ores freed from rock, before pounding by the "ghun." 6th.-Ore mixed with cow-dung and roasted, as put into the smelting furnace. 7th.-Slag picked up from mounds, (evidently still containing copper). 8th.- Alum shale with sulphate of copper; (average specimen). 9th.-Sulphate of copper after first boiling. 10th. Sulphate of copper (purified). 11th.-Alum after first boiling. 12th.-Ditto, (purified). 13th.-Sulphate of iron found in combination with the other sul. phates. 14th.-Impure residue of alum, sulphate of copper, and nitrate of potash. 15th.-Ores, of which the miners desire an analysis. 16th.-Fossil wood encrusted with copper ore as dug out of the copper mines. 17th.-Cobalt ore, called by natives "Sheta," as found in the mines mixed with copper pyrites. 18th. Ditto, ditto pounded. In the box in which the above have been sent, are specimens of other ores, having, however, no connection with Khetree or its copper mines, viz. 19th.-Zinc ores from zinc mines at Jawur near Oodepoor in Meywar; not now worked. The specimens were struck off the rock in an old working. 20th.-Specimens of crude yellow ochre from near the same place. 21st.-Choice and beautiful specimens of carbonates and sulphates of lead from the lead mines at Ajmere. 22nd.-Antimony from the same mines. Note on the hail-storm of Thursday the 24th March.-By HENRY F. [Received 6th April, 1864.-Read 6th April, 1864.] The formation of hail is well known to be one of the most obscure phenomena of meteorology, more especially in the case of hail-stones of unusual size, which, from the very circumstances of the case, must be formed within the space of the few seconds succeeding the consolidation of their nuclei, and during which they are falling, in obedience to the law of gravity. In tropical climates, where the temperature at a considerable height from the earth is much above the freezing point, and where nevertheless, some of the largest recorded hail-stones have fallen, the stones must attain their maximum dimensions in the first portion of their fall, and during some subsequent seconds, must be subject to the liquifying influence of the lower and denser strata of the atmosphere. It has appeared to me therefore that a few observations on the stones which fell in Calcutta in a hail-storm on Thursday the 24th ultimo, may be not without interest as a contribution to this branch of Meteorology. For the thermometric, barometric and anemometric observations I am indebted to Col. Thuillier, the Surveyor-General. The storm commenced about to 6 in the afternoon, the wind being from the south-east, and for a few minutes previous to the fall blowing in strong intermittent gusts, though not stronger than commonly precede the afternoon showers of this season. * The clouds, a thick mass of nimbus, approached or formed from the north-west, but did not move at any great rate, and indeed they appeared to be stationary during the latter part of the storm. Lightning was frequent, and forked, radiating in zig-zags from a small mass of cloud to those around, and the thunder was frequent and almost continuous, but not loud. Heavy drops of rain began to fall at to 6, and were soon accompanied by a few hail-stones about the size of hazel nuts. They were not very numerous, At the Botanic Gardens, the stillness of which is more favourable to observ. ation than the noise of Chowringhee, Dr. Anderson noticed that the storm was preceded by a prolonged rushing sound, similar to that which would be produced by a number of railway trains rushing by at no great distance. This increased gradually, apparently from the north or north by west, and appeared to pass overhead, before the hail fell. The direction of the hail near the ground was from the south-east. |