NATURAL PHILOSOPHY. 155 



Direction of the Wind. Professor Airy has observed some curious 

 facts respecting the direction of the wind. It seems that there are 

 only eight points of the compass from which the wind ever blows stead- 

 ily ibr any length of time, namely, the S. S. W., the W. S. W. a point 

 between the W. and N. W., another between the N. and E., another 

 between E. and S. S. W., theN., the W., and the E. The wind never 

 blows directly from the south. 



PRESSURE OF THE ATMOSPHERE, OCEAN, ETC. 



The following novel views respecting the pressure of the atmosphere, 

 and of the waters of the ocean at varying depths have been communi- 

 cated by Mr. C. E. Townsend, Esq., of Tompkinsville, N. Y. : 



According to the philosophy of the day, the pressure of the atmos- 

 phere at sea-level is calculated at fifteen pounds for every square 

 inch, being equal to a column of water one inch broad and thirty- 

 three feet in height , and every thirty-three feet descent into the ocean 

 adds an additional fifteen pounds pressure, over every square inch, 

 thus augmenting the density of parts beneath in proportion to the 

 superincumbent pressure. Recent discoveries prove that a high order 

 of radiate animals and fleshy inhabitants of shells, in vast numbers, 

 are found living at the bottom of the ocean one and a hah miles 

 down. 



In a paper from Dr. I. C. Wallack, in the Scientific Annual for 

 1862, page 344, Professor Agassiz, is made to say " that animals sub- 

 ject to such enormous pressure, to avoid being crushed by the weight, 

 from depths at fifteen pounds for every thirty-three feet descent, must 

 admit water very freely through their tissues." Surely such explana- 

 tion must be unsatisfactory, for the animal tissues remaining, they could 



little heavier than surface water, is supposed to sink to the bottom, 

 whatever that depth may be, and to enable it to do so, in accordance 

 with the above estimates of increasing pressure, must have its bulk di- 

 minished 240 times to enable it to sink into the lower stratum, whose 

 density is equal to 3600 pounds to the square inch. Thus a block of 

 wood six inches square, would have to be reduced by successive pres- 

 sures to a little less than one inch square, to reach the bottom. Animal 

 life could not exist subject to such disorganizing pressures and survive 

 on being brought to the surface, subject to a corresponding inflation, 

 and yet we know animals do live at the bottom, and are brought, to the 

 surface alive. Indeed, according to this old philosophy, the shells must 

 be subject to the same contraction and expansion, which is hardly a 

 supposable case. 



It is said that animal bodies, on the surface of the earth, support a 

 pressure of fifteen pounds to every square inch, which is equal to 30,- 

 000 pounds pressure for the average size of man ; and to enable him to 

 bear this weight (for it is not supposed that his muscular power is 

 equal to the task), it is contended that the pressure exists equally on 

 all sides, pressing with equal force upwards, downwards, sideways, in- 

 wards and outwards, thus confessedly making such supposed weight a 

 nullity. As this same pressure acts on the same principle throughout 



