Curiosities of Science. 151 



main in apartments, and on the surface of the soil. Now, 

 of all winds, that which causes the greatest ascension of the 

 barometric column is the east; and that which lowers it most 

 is the west. When the latter blows, it carries with it to the 

 eastern parts of the town all the deleterious gases from the 

 west ; and thus the inhabitants of the east have to support 

 their own smoke and miasma, and those brought by western 

 winds. When, on the contrary, the east wind blows, it purifies 

 the air by causing to ascend the pernicious emanations which it 

 cannot drive to the west. Consequently, the inhabitants of the 

 west receive pure air, from whatever part of the horizon it may 

 arrive ; and as the west winds are most prevalent, they are the 

 first to receive the air pure, and as it arrives from the country. 



FERTILISATION OF CLOUDS. 



As the navigator cruises in the Pacific Ocean among the 

 islands of the trade-wmd region, he sees gorgeous piles of cu- 

 muli, heaped up in fleecy masses, not only capping the island 

 hills, but often overhanging the lowest islet of the tropics, and 

 even standing above coral patches and hidden reefs ; " a cloud 

 by day." to serve as a beacon to the lonely mariner out there at 

 sea, and to warn him of shoals and dangers which no lead nor 

 seaman's eye has ever seen or sounded. These clouds, under 

 favourable circumstances, may be seen gathering above the low 

 coral island, preparing it for vegetation and fruitfulness in a 

 very striking manner. As they are condensed into showers, 

 one fancies that they are a sponge of the most exquisite and de- 

 licately elaborated material, and that he can see, as they " drop 

 down their fatness," the invisible but bountiful hand aloft that 

 is pressing and squeezing it out. Maury. 



BAROMETRIC MEASUREMENT. 



We must not place too implicit a dependence on Barometri- 

 cal Measurements. Ermann in Siberia, and Ross in the Antarc- 

 tic Seas, have demonstrated the existence of localities on the 

 earth's surface where a permanent depression of the barometer 

 prevails to the astonishing extent of nearly an inch. 



GIGANTIC BAROMETER. 



In the Great Exhibition Building of 1851 was a colossal 

 Barometer, the tube and scale reaching from the floor of the 

 gallery nearly to the top of the building, and the rise and fall 

 of the indicating fluid being marked by feet instead of by tenths 

 of inches. The column of mercury, supported by the pressure 

 of the atmosphere, communicated with a perpendicular tube of 



