32,° 42.• 52.° 62.• 72.o 82 ° 92.• 102.o 112." 122.o 132.o 142.• 152.* 162, 172.o 182.o 192.* 202.* 212.” 0. 2. 3. 6. 9. 11. 12. 14. 17. 19. 21. 23. 25. 27. 30. 33. 35. 38. 40. VOL. II. SECOND SERIES. After what has been said, I need not caution my readers not to consider this table as accurate. The principle of it, however, cannot, I conceive, be dis proved that the operation of the conducting power must be proportionate to a series of numbers beginning from 0 at 32°, and gradually increasing, in some ratio, with the temperature above 32°, cannot, I think, be controverted; and that the operation of the internal motion must begin from 0 at 32o, and increase till it arrives at its maximum at 42°, and then decrease again ever after, is also, I apprehend, unquestionable; thus, when the jar had water of 42°, in Count Rumford's experiments, this internal motion must have had a range of eight inches in depth; whereas, when hot water alone was used, it had not more than three-fourths of an inch to range from the temperature of 32 to that of 53°. The following table exhibits a concise view of all the material varieties of Count Rumford's experiments, with their result, Experiment Count Rumford attempts to explain why there was less ice melted in such experiments as the 45th than in those like the 39th, and attributes the diminution of the effect to the descending currents, occasioned by the cold mixture surrounding the warm one, which he thinks would obstruct the opposite ones ascending from the ice. But the effect in the 51st compared with the 53d, being just. opposite, he passes over without explanation.-I have no doubt myself, but that the true cause of the differences in both cases, is to be found in the column expressing the mean temperature of the water, and not in that expressing its situation, which I consider as having nothing to do in the business, but as it affects the general temperature. The maximum effect with cold water will be when it is of the temperature of about 48° or 50°, and the minimum above is probably about 100* or 120°; and in proportion as the mean temperatures, in any experiment, deviate from those points, the effects vary accordingly, let other circumstances be what they may. Thus I have attempted to explain the rationale of these very curious and interesting experiments, in a manner different to what their ingenious author has done. And must now leave it to the reader to form his opinion. An An Account of Experiments on the Culture of Beans and Wheat in one Year on the same Land. By Mr. ROBERT BROWN, ef Markle, near Haddington, in Scotland. From the TRANSACTIONS of the SOCIETY for the Encou ragement of ARTS, MANUFACTURES, and COMMERCE. The Silver Medal was presented to Mr. BROWN for this Communication. I TAKE the liberty of transmitting to you an account of eighty-eight and a half acres of land, drilled with beans in the months of February and March 1798; amongst which a few peas were mixed, in order to improve the straw as fodder for horses, and for making ropes to tie the crop. The whole of the said land was sown with wheat in the month of October, the same year. I shall shortly state the mode of managing the beans. The land was first cross-ploughed during the preceding winter, and about 20 acres were dunged previous to this furrowing being given, and 10 acres more in the spring, when the beans were drilled. The quantity of dung". applied to the acre was about 12 cart-loads, each drawn by 2 horses, the weight of which might be about a ton. The land at seed-time was clean ploughed over, and the drill-barrow followed every third plough, which gave an interval between the rows of 26 or 27 inches. The quan tity of seed sown was from 17 to 19 pecks per acre, as those who managed the drill sometimes, from inattention, allowed it to sow a degree thicker at one time than another. The kind of beans sown was the common horsebean, mixed, as I have already said, with a trifling quan tity of peas; and the average produce per acre of the whole fields sown was nearly 36 bushels per acre, the pro duce |