312 PRESSURE IN THE AIR, 



from the top to the bottom, is in the proportion 

 of 15 or 16 Ibs. to every square inch of surface- 

 and as there are 144 square inches to every 

 square foot, these : must consequently sustain a 

 pressure of weight equal to 2,880 Ibs. supposing, 

 therefore, that a man in an erect posture covers 

 a surface commensurate to a square of 16 

 inches, (a calculation very moderate,) it must, in 

 that case, follow, that the perpendicular pres- 

 sure upon him, is equal in weight to 2,880 Ibs. 

 But, alas ! if he should have lips thick nose 

 flatcheek-bones prominent ears expanded 

 hat broad-brimmed, a parasol to keep off the 

 sun, or a parapluie to shelter him from the rain, 

 the weight must, in that case, be as great, as 

 it is when he is in a recumbent position ; or 

 when the superficies of his body may be conse- 

 quently supposed to be increased, at least, to a 

 square of eight feet; it is affirmed, and very 

 justly affirmed, if the positions were true from 

 which these conclusions are drawn, that such 

 a one must sustain a weight of 15,370 Ibs. that 

 is to say, more than seven tons weight, for his 

 Ordinary load!!! It was from data such as 

 these, that Mr. COTES, and others, conceived 

 that they had been able, with precision, to cal- 

 culate the absolute pressure of dead weight of 

 the whole ambient air, impending over the 

 globe in general, and this country in particu- 

 lar. The superficial surface of England, is 



