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Show HEAT OF THE SUN. Progress in the work of exact do-termination do-termination of the amount of heat re ceived by the earth from the sun, which has been the object of experiments experi-ments recently conducted by Messrs C. G. Abott. F. E Fowle and L. B. Aid-rich Aid-rich of the Smithsonian institution, at Washington, is described by these scientists sci-entists in the June number of the Proceedings of the National Academy of Sciences. They have found that the amount of heat is 1.93 calories per square centimeter cen-timeter per minute: that is to say, enough heat Is received from the sun on each square yard to heat a pound of water to boiling in 2 1-2 minutes The heat which is received at the earth's surface is somewhat less than this, namely by the variable amount that is absorbed bj the earth's atmosphere atmos-phere The remarkable discovery has also been made that the heat received from the suu is not constant but variable vari-able from month to month or year to year by perhaps as much as 10 per cent. This variation might be expected expect-ed to make pronounced differences in the growth of vegetation or in the general gen-eral climate from year to year; but for some reason, perhaps through the variable effects of the earth's atmosphere, atmos-phere, the variations in the heat received re-ceived from the sun seem to be unimportant unim-portant so far as crops are eoncpmed The National Academy of Sciences has recently made an appropriation of $250 to Dr Abbott for the purpose of enabling him to complete and test, on Mount Wilson In California, an apparatus appa-ratus consisting of a concave cylindrical cylindri-cal mirror of about 100 square feet surface for concentrating the sun's heat on tubes containing oil. which is then made to circulate through a reservoir res-ervoir containing ovens and water pipes, so as to utilize solar radiation for cooking and heating water for domestic do-mestic purposes. |