No. 9. 



Pressure of the Atmosphere. — Duke of Athol. 



277 



to fabricate a mountain of manure at home, 

 and be doing a service at tlie same time, in 

 the way of improving their homesteads and 

 increasing their comforts. But I suppose it 

 would be difficult to please one who has an 

 inkling after old pleasures and time on his 

 hands to criticise his neiffhbours, else I would 

 ju!*t intimate that the plan which 1 see is 

 beginning to be adopted, namely, to plough 

 up a bank or rough fence-row, and carry on 

 it manure from the cattle-yard, all to be turn- 

 ed together to form a compost-heap, might be 

 much improved, by first skim-ploughing the 

 rough surface and burning it; then to spread 

 the ashes and plough as deep as the surface- 

 soil will permit; then harrow and turn up 

 -again, by which tiie ashes will be well mixed ; 

 and upon this, place the dung, turning all to- 

 gether as a compost-heap — "a mountain of 

 labour," I hear some one exclaim, " and what 

 can ever pay the expense ?" I answer, the 

 crops, and let no one hesitate to charge them 

 with it. J. H. 



PJiilad., March 28. 1842. 



Pressure of the Atmosphere. 



The weight of the atmosphere is near fif- 

 teen pounds on every square inch, so that if 

 we could entirely squeeze out the air between 

 our two hands, they would cling together 

 with a force equal to the pressure of double 

 this weight, because the air would press upon 

 both hands; and if we could contrive to suck 

 or squeeze out the air between one hand and 

 the wall, the hand would stick fast to the 

 wall, being pressed on it with the weight of 

 above 200 pounds, near fifteen pounds on 

 every square inch of the hand ! Now, by a 

 late most curious discovery of Sir Everard 

 Home, the distinguished anatomist, it is found 

 that this is the very process by which flies 

 and other insects of a similar description are 

 enabled to walk upon perpendicular surfices, 

 however smooth, as the sides of walls and 

 panes of glass in windows, and to walk as 

 easily along the ceilings of rooms with their 

 bodies downwards and their feet overhead. 

 Their feet, when examined by a microscope, 

 are found to have flat skins or flaps, like the 

 feet of web-footed animals, as ducks and 

 geese ; and they have, by means of strong 

 folds, the power of drawing the flap close 

 down upon the glass or wall the fly walks 

 on, and thus squeezing out the air completely, 

 so as to make a vacuum between the foot and 

 the glass or wall. The consequence of this 

 is, that the air presses the foot on the wall 

 with a very considerable force compared to 

 the weight of the fly; for if its feet are to its 

 body in the same proportion as ours are to 

 our bodies, since we could support by a single 

 hand on the ceiling of the room (provided it 



made a vacuum) more than our whole weight, 

 namely, a weight of over 200 pounds, the 

 fly can easily move on four feet in the same 

 manner by help of the vacuum made under 

 its feet. And it has likewise been found that 

 some of the larger sea animals are, by the 

 same construction, enabled to climb the per- 

 pendicular and smooth surfaces of the ice hills 

 among which they live. Some kinds of liz- 

 ards have the same power of climbing and of 

 creeping with their bodies downward along 

 the ceiling of a room, and the means by which 

 they are enabled to do so, are the same. And 

 in the large feet of those animals the contriv- 

 ance is easily observed, of the toes and mus- 

 cles by which the skin of the foot is pinned 

 down and the air excluded in the act of walk- 

 ing or climbing; but it is the very same, only 

 upon a larger scale, with the mechanism of a 

 fly's or a butterfly's foot ; and both operations, 

 the climbing of the sea-horse on the ice, and 

 the creeping of the fly on the window or the 

 ceiling, are performed exactly by the same 

 power, the weight of the atmosphere, which 

 cnuses the quicksilver to stand in the wea- 

 ther-glass, the wind to whistle through a key- 

 hole, and the piston to descend in an old 

 steam-engine ! — Brotis:ham. 



Duke of Athol. 



The estate of the present Duke of Athol, 

 "is immense, running in one direction more 

 than seventy miles. On hie estate there are 

 thirty-six miles of private road for a carriage, 

 and more than sixty miles of well-made walks, 

 which are being extended every year. These 

 roads and paths being made for pleasure, are 

 laid through the most picturesque and roman- 

 tic scenery; along the river's bank, up the 

 glen, cut in the steep sides of the mountains 

 and over their tops, and along the margin of 

 the precipitous cliffs — now into the forest 

 gloom — now opening on a boundless prospect, 

 or some sweet vale — now bursting on a wa- 

 terfall, and next along the side of a murmur- 

 ing brook. The father of the present duke 

 began in his lifetime one of the most magnifi- 

 cent palaces in the kingdom. It is said that 

 in the estimate of the cost of the edifice, the 

 single item of raising the walls and putting on 

 the roof, together with the materials, would 

 have been one hundred thousand pounds, 

 about five hundred thousand dollars." 



Do you envy the possessor of all thia 

 wealth ? 



For more than thirty years he has been in 

 a lunatic asylum of London. 



Agriculture, like the leader of Israel, 

 strikes the rock — the waters flow, and the 

 tarnished peonle are satisfied — she supplies, 

 she feeds, she quickens all. 



