150 



THE CHRISTIAN PHILOSOPHER. 



diameter of the orbit he would describe ; and the 

 circle B C D E the circumference along which 

 he would move every day, or 597 millions of 

 miles, which is somewhat more than three times 

 the diameter. If the line A F represent the dis 

 tance of the nearest star, the circle F G H I will 

 represent the circuit through which it would 

 move every 24 hours, if the earth were at rest. 

 It is obvious, from the figure, that since the stars 

 are at a greater distance from the earth than the 

 sun, the circle they would describe around the 

 earth would he larger in proportion, and, conse 

 quently, their velocities would be proportionably 

 more rapid ; since they would move through 

 their larger circles in the same time in which the 

 sun moved through his narrow sphere. But the 

 supposition that the earth is the centre of all the 

 celestial motions, and that the different stars are 

 daily moving around it with different velocities, 

 and the slowest of these motions is so inconceiva 

 bly rapid is so wild and extravagant, that it 

 appears altogether inconsistent with the harmony 

 of the universe, with the wisdom and intelli 

 gence of the Deity, and with all the other ar 

 rangements he has made in the system of nature. 



No. II. p. 34. Experimental illustrations of 

 the Pressure of the Atmosphere, 



The pressure of the atmosphere is most strik 

 ingly illustrated by means of the air-pump. But 

 as few persons, comparatively, possess this in 

 strument, the following experiments, which any 

 person may perform at pleasure, are sufficiently 

 convincing on this point. Take a common 

 wine-glass, and fill it with water; apply a piece 

 of paper over the mouth of the glass ; press the 

 paper to the rim of the glass with the palm of 

 the hand ; turn the glass upside down ; with 

 draw the hand from the paper, and the water 

 will be supported by the pressure of the atmos 

 phere. That it is the atmospherical pressure, 

 and not the paper, which supports the water, is 

 evident ; for the paper, instead of being pressed 

 down by the weight of the water, is pressed 

 upward by the pressure of the atmosphere, and 

 nppears concave, or hollow in the middle. If the 

 flame of a candle be applied to the paper, it 

 may be held, for an indefinite length of time, 

 close to the paper, without setting fire to it. 

 The same fact is proved by the following expe- 

 -iment : Take a glass tube, of any length, and 

 of a narrow bore ; put one end of it in a basin 

 of water ; apply the mouth to the other end, 

 and draw out the air by suction , the water will 

 immediately rise toward the top of the tube ; 

 and if the finger or thumb be applied to the top 

 of the tube, to prevent the admission of air, and 

 the tube removed from the basin of water, the 

 water in the tube will be supported by the pres 

 sure of the atmosphere on the lower end. Again : 

 Take a wine-glass, and burn a small bit of 



paper in it ; and when the paper is burning 

 press the palm of the hand upon the mouth of 

 the glass, and it will adhere to the hand with 

 considerable force. In this case, the pressure 

 of the atmosphere will be sensibly felt : for i: 

 will sometimes require considerable force to de 

 tach the glass from the hand. 



The pressure of the atmosphere explains a 

 variety of common phenomena. When we take 

 a draught of water out of a basin, or a running 

 stream, we immerse our mouths in the water, 

 and make a vacuum by drawing in the air ; the 

 pressure of the atmosphere upon the external 

 surface of the water then forces it into the 

 mouth. The same cause explains the process 

 of a child sucking its mother s breasts the ac 

 tion of a boy s sucker, in lifting large stones 

 the rise of water in pumps the effects produced 

 by cements the firm adhesion of snails and 

 periwinkles to rocks and stones the scarcity of 

 water in the time of hard frosts and the fact 

 that a cask will not run by the cock, unless a 

 hole be opened in some other part of the cask. 



No. III. p. 118. On the means by which it 

 may probably be ascertained whether the Moon 

 be a Habitable World. 



About six years ago, the author published, in 

 the Monthly Magazine, a few observations on 

 the surface of the moon, in which a few remarks 

 were offered on this subject. The following is 

 an extract from that communication : 



&quot; If we be ever to obtain an ocular demon 

 stration of the habitability of any of the celestial 

 orbs, the moon is the only one, where we can 

 expect to trace, by our telescopes, indications 

 of the agency of sentient or intelligent beings ; 

 and I am pretty much convinced, that a long 

 continued series of observations on this planet, 

 by a number of individuals in different places, 

 might completely set at rest the question, Whe 

 ther the moon be a habitable world? Were a 

 vast number of persons, in different parts of the 

 world, to devote themselves to a particular sur 

 vey of the moon were different portions of her 

 surface allotted to different individuals, as the 

 object of their particular research were every 

 mountain, hill, cavern, cliff, and plain accurately 

 inspected and every change and modification 

 in the appearance of particular spots carefully 

 marked and represented in a series of delinea 

 tions, it might lead to some certain conclusions, 

 both as to her physical constitution, and her 

 ultimate destination. It can be demonstrated, 

 that a telescope which magnifies 100 times, 

 will show a spot on the moon s surface, whose 

 diameter is 1223 yards ; and one which magni 

 fies a thousand times, will, of course, enable ug 

 to perceive a portion of her surface, whose size 

 is only 122 yards : and, consequently, an object, 

 whether natural or artificial, of no greater extent 



