32 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



without their being moved by the wind, while at a distance 

 of from twenty to thirty paces in his rear the trees were bend- 

 ing with the force of the gale. He subsequently, again and 

 again, observed this phenomenon when a high wind would 

 strike a vertical rock at right angles. By this he was led to 

 conclude that a mass of air in rapid motion, meeting with an 

 extensive perpendicular obstacle, is forced upward some dis- 

 tance above its upper edge, and then flows over like a wa- 

 ter wave, thereby protecting a belt against the direct wind. 

 Professor G. Torchhammer also, repeatedly noticing, in Jut- 

 land, that in stormy weather sheep congregated close to the 

 edges of precipices, found a perfect calm prevailing at such 

 points. Another observation would appear to confirm the 

 correctness of the above explanation. A cloud was seen for 

 nearly a whole day hovering on a level with the summits of 

 the rocks of Gibraltar, though during the entire time an east- 

 erly gale was blowing, from which it would appear that the 

 upward current created by the resistance of- the rocky wall 

 prevented the cloud from following in the direction of the 

 wind. 7(7, 1871,180. 



' COLD OX MOUNT WASHINGTON. 



Among the experiences of the Mount Washington winter- 

 party may be mentioned an exposure to perhaps the greatest 

 cold ever recorded in the annals of science. The temperature 

 was 50, and to this was added a hurricane blowing at the 

 rate of one hundred miles an hour. The combination of such 

 a wind with the temperature indicated would probably have 

 been entirely unsupportable but for the means of protection 

 enjoyed by the party in the dwelling which had been fitted 

 up expressly for their accommodation. 



STORM SIGNALS IN THE UNITED STATES. 



It is stated in some of the papers that the system of storm 

 signal observations now in progress under the direction of 

 the Signal Corps of the army Avas devised by Great Britain 

 before it was made use of by the United States government. 

 This is perhaps correct so far as it goes; but it is to Profess- 

 or Henry, Secretary of the Smithsonian Institution, that we 

 owe the original idea of procuring dispatches regularly in re- 

 lation to the weather, and tabulating them, as also of placing 



