150 Things not generally Known. 



THE PUBEST ATMOSPHEEES. 



The cloudless purity and transparency of the atmosphere, 

 which last for eight mouths at Santiago, in Chili, are so great, 

 that Lieutenant Gilliss, with the first telescope ever constructed 

 in America, having a diameter of seven inches, was clearly able 

 to recognise the sixth star in the trapezium of Orion. If we 

 are to rely upon the statements of the Rev. Mr. Stoddart, an 

 American missionary, Oroouaiah, in Persia, seems to be, in so 

 far as regards the transparency of the atmosphere, the most 

 suitable place in the world for an astronomical observatory. 

 Writing to Sir John Herschel from that country, he mentions 

 that he has been enabled to distinguish with the naked eye the 

 satellites of Jupiter, the crescent of Venus, the rings of Saturn, 

 and the constituent members of several double stars. 



SEA-BREEZES AND LAND-BREEZES ILLUSTRATED. 



When a fire is kindled on the hearth, we may, if we will 

 observe the motes floating in the room, see that those nearest 

 the chimney are the first to feel the draught and to obey it, 

 they are drawn into the blaze. The circle of inflowing air is 

 gradually enlarged, until it is scarcely perceived in the remote 

 parts of the room. Now the laud is the hearth, the rays of the 

 sun the fire, and the sea, with its cool and calm air, the room ; 

 and thus we have at our firesides the sea-breeze in miniature. 



When the sun goes down, the fire ceases ; then the dry laud 

 commences to give off its surplus heat by radiation, so that by 

 nine or ten o'clock it and the air above it are cooled below the 

 sea temperature. The atmosphere on the land thus becomes 

 heavier than that on the sea, and consequently there is a wind 

 seaward, which we call the land-breeze. Maury. 



SUPERIOR SALUBRITY OF THE WEST. 



All large cities and towns have their best districts in the 

 West ;* which choice the French savans, Pelouze, Pouillet. 

 Boussingault, and Elie de Beaumont, attribute to the law of 

 atmospheric pressure. " When," say they, " the barometric 

 column rises, smoke and pernicious emanations rapidly evapor- 

 ate in space. On the contrary, smoke aud^noxious vapours re- 



* Not only at London, but at Paris, Vienna, Berlin, Turin St. Petersburg, 

 and almost every other capital in Europe ; at Liege. Caen, Montpellier. Toulouse, 

 and several other large towns. wherever, in fact, there are nut great local obsta- 

 cles, the tendency of the wealthier inhabitants to group themselves to the west 

 is as strongly marked as in the British metropolis. At Pompeii. tid other an- 

 cient towns, the same thing may be noticed ; and where the local configuration of 

 the town necessitates an increase in a different direction, the moment the obsta- 

 cle ceases houses spread towards the west. 



