RESULTS OF METEOROLOGICAL OBSERVATIONS MADE AT THE *To obtain the Barometric pressure at the sea-level, these numbers must be increased by '037 inch. HOURLY MOVEMENT OF THE WIND (IN MILES), AS RECORDED BY ROBINSON'S ANEMOMETER.-AUGUST, 1867. Hour. 12 296 7625469a 2433 4 3 9 4 13 4 13 311 2902 25579 13 9 12 12 10 14 1934B67 10256 8464888 433542 66 99796 98873 2657725220034 34 294 209 83 90 205 207 176 285 244 130 61 203 221 87 163 218 418 252 142 312 148 99 96 130 192 127 111 191 170 228 227 90 9.0 83 X RESULTS OF METEOROLOGICAL OBSERVATIONS MADE AT THE *To obtain the Barometric pressure at the sea-level, these numbers must be increased by ⚫037 inch. HOURLY MOVEMENT OF THE WIND (IN MILES), AS RECORDED BY ROBINSON'S ANEMOMETER. SEPTEMBER, 1867. 89 Hourly 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Means. 216 10 421 5 1 15 1 9 5 1 16 2 7 54 4 1 10 9 5 11 29612 1 12 11 8 16 4 12 12 458 13 12 8 11 13 11 13 10 10 15 15 12 10 15 16 12 10 12 15 19 12 14 16 20 13 13 11 20 745422 9 20 10 19 6 16, 311 7641 865 4 1 10 2 15 1 9 1 11 1 6 1 10 1 1 169TO 8 10 12 4412 5577 554 11 1 4 7 6668 3 10 13 8 11 22 113426 15 4 9 13 22 3 13 4 9 4 14 8 10 3 15 10 10 3 13 15 $ 7.6 5 14 16 14 10.1 17 14 12 13 27 9 10 4 13 18 19 12:0 15 2 17 11 15 13 24 10 10 15 6 16 13 15 16 26 13 13 19 8 18 11 12 17 28 13 12 14 14 17 12 15 18 11 12 15 12 13 8 8 11 2222 3 14 19 18 12:2 3 10 15 20 13.7 4 8 18 17 14:4 22 8 20 14 15 20 23 10 9 4 12 16 18 14.9 16 11 19 15 11 19 25 6 12 16 18 14:5 12 19 17 14.9 19 13 137 12.6 17 10 20 12 11 19 26 15 6 22 12 9 18 22 7 6 16 10 10 18 22 11 10 19 10 10 21 5 10 11 17 5 21 5 19 7 7 17 5 9 19 136 11 19 11 8 169 11-2 5 7 13 9.6 8.4 8.2 42 242 8:0 175 211 233 283 268 394 355 182 149 238 172 288 123 322 225 207 298 476 197 198 145 254 325 258 10:4 The Anemometer was dismounted on the 25th, for the purpose of erecting a new instrument on the pattern decided upon for the Board of Trade observatories. NOVEL ACTION OF LIGHT. BY NIEPCE DE ST. VICTOR. (Translated from "Comptes Rendus," No. 12, 1867). I HAVE published, in five preceding memoirs all the experiments which I have made to prove that porous or rough bodies which have been acted upon by light preserve an activity capable of reducing salts of silver in the dark, as though they had been exposed to light. I have shown that this activity is persistent; that it is preserved for many days in obscurity or in the free air; that if a body had lost this activity, it could be made to resume it on exposing it again to light; that, supposing a piece of cardboard, was insolated, having been impregnated with nitrate of uranium, or tartaric acid, and shut up in a confined atmosphere, such as a tin case, hermetically sealed, it would have the same activity after several months as it showed on the first day. This activity acts at a certain distance in the dark, for instance, and is communicated to a similar body in the same way, but the action does not pass through the glass. M. Arnaudon, a chemist of Turin, has repeated some of my experiments in different gases, and the results have been the same as in free air. It would be very important to make an experiment in a luminous vacuum, but I have not as yet been able to do it. I proved the production of this activity upon the edges of a newly-broken china-plate, as well as upon an unpolished sheet of glass, made perfectly clean. with distilled water. It could not be said, therefore, in this case, that there was decomposition of the body acted upon by light. I have shown that the effects of light are not owing to phosphorescence, but I have not said whence this activity comes. Many hypotheses have been put forward. Certain persons have denied the fact altogether, which was more simple; but no one has given a solution to this phenomenon. I said, in my first memoir, that an engraving or a plain sheet of paper having been insolated and afterwards placed on a layer made sensitive to light, such as iodide or chloride of silver, reduces salts of silver in obscurity, as though they had been exposed to light, only much more rapidly. If the sheet is impregnated with nitrate of uranium, or tartaric acid, before being exposed to the light, the reduction of the salts of silver is very quick, especially with the first substance. This is, then, my experiment. I placed seven strips of red, orange, yellow, green, blue, indigo and violet glass |