VOL. I.] PHILOSOPHICAL TRANSACTIONS. 21 



influence of the manifest eflficient causes, as the hght of the air depends upon 

 the sun or fire, or other luminous bodies ? To this is annexed an account of the 

 Italian way of making conservatories of ice and snow, as the author had received 

 it from that ingenious and polite gentleman, Mr. J. Evelyn. 



It shall only be intimated for a conclusion, that the author has annexed to this 

 treatise, an examen of M. Hobbs's doctrine touching cold ; wherein the grand 

 cause of cold and its effects is assigned to wind, insomuch that it is affirmed, 

 that almost any ventilation and stirring of the air doth refrigerate. 



Extraordinary Tides in the IFest-Isles of Scotland. By Sir Robert 



Moray, iV° 4, p. 53. 



In that tract of isles, on the west of Scotland, called by the inhabitants the 

 Long Island, (from being about 100 miles long from north to south) there is a 

 multitude of small islands, situated in a fretum, or frith, - amongst which there 

 is one called Berneray, three miles long, and more than a mile broad, the length 

 running from east to west, as the Frith lies. At the east end of this island I 

 observed a very strange reciprocation of the flux and reflux of the sea ; and I 

 was told of another no less remarkable. 



Upon the west side of the Long Island, the tides which came from the south- 

 west run along the coast northward ; so that during the ordinary course of the 

 tides, the flood runs east in the Frith where Berneray lies, and the ebb west. 

 And thus the sea ebbs and flows orderly about four days before the full moon 

 and change, and as long after. But for four days before the quarter moons, and 

 as long after, there is constantly a great and singular variation. For then (a 

 southerly moon making there the full sea) the course of the tide being eastward, 

 when it begins to flow, which is about Qi of the clock, it not only continues so till 

 about 3i in the afternoon, when it is high water, but after it begins to ebb, the 

 current runs on still eastward, during the whole ebb ; so that it runs east- 

 ward 12 hours together, that is, all day long, from about Q^ in the morning 

 till about Q-^ at night. But then, when the night-tide begins to flow, the cur 

 rent turns, and runs westward all night, during both flood and ebb, for about 

 12 hours more, as it did eastward the day before. And thus the reciprocations 

 continue, one flood and ebb running 1 2 hours eastward, and another 1 2 hours 

 westward, tiM four days before the new and full moon ; and then they resume 

 their ordinary regular course as before, running east during the six hours of 

 flood, and west during the six of ebb. 



I was also informed that there is yet another irregularity in the tides, which 

 never fails, and is no less extraordinary than what I have been mentioning ; 

 which is. That whereas between th vemale and autumnal equinoxes^ that is^ 



