183 



EECEEATIVE SCIENCE. 



have an exception to tliat cruel way of gain- 

 ing Lis aflfections. Tlie dog in question Lad 

 been well trained, and who can doubt his 

 pride was wounded by the reception of un- 

 merited blows ? But did he understand the 

 meaning of those terrible words, " I'll shoot 

 you," and fearing the murderous threatwould 

 be executed, deem discretion the better part 

 of valour P 



Michael Westcott. 

 Wells, Somerset. 



A PHILOSOPHEE IN A EAILWAY 

 TEAIN. 



It is, in every case, instructive to illustrate 

 celestial phenomena by others within the 

 range of terrestial existence. To those who 

 are but slightly conversant with the more 

 recondite facts and speculations connected 

 with the physical sciences, this method is 

 peculiarly useful, while from all it is worthy 

 of regard. The phenomenon before us being 

 well understood I need not explain it, but 

 will proceed to show that it may be illus- 

 trated, in fact experienced, as regards mun- 

 dane objects ; and this in a simple manner. 

 It would be well if all who have any know- 

 ledge of physical science would endeavour to 

 discover some such illustrations as the one I 

 am about to give, towards which acquisition 

 I hope this communication will tend. 



This phenomenon may be illustrated in 

 many ways ; but, as the nature of all must 

 from necessity be similar, I shall describe 

 only one. If any person is travelling at night 

 in a railway carriage, on a portion of line 

 where some branch or line meets his, and 

 observes the lights of an approaching train 

 on that line, they will appear to travel to- 

 wards him far more perpendicularly than is 

 really the case, because of his motion, which, 

 for the time, he should endeavour to forget. 

 When he reaches the junction of the lines, 

 any particular light represents the rays 



emanating from any star or planet. The 

 explanation of this is very simple : The car- 

 riage represents our earth, the rapid motion 

 of which is not obvious to the senses; the 

 lights on the distant railway illustrate the 

 rays proceeding from the celestial bodies, 

 whether obviously in motion or comparatively 

 quiescent ; these are seen approaching, ap- 

 parently at no very acute angle, which is thus 

 increased, or rather appears to be, from the 

 motion of the carriage. They represent, 

 then, a ray on its progress to the earth, and 

 where the lines join, its impact upon the eye, 

 which appears to be at a far less acute 

 angle than reason proves to be the case. 

 Thus it appears that the motion of the car- 

 riage produces this eflfect, corresponding to 

 the delusion consequent upon the motion of 

 the earth, which motion causes the stars to 

 appear crowded towards the zenith. The dif- 

 ference in angular variation produced upon 

 the fixed stars and planets, although full 

 worthy of notice, does not, of course, affect 

 this principle, and, consequently, need not 

 here be noticed. To render the explanation 

 more perfect, I remark that the rays proceed- 

 ing from the lamps before they reach the 

 place where the lines join, do not illustrate 

 those coming from the stars, except as ex- 

 periencing, or being experienced, in connec- 

 tion with the motion of the carriage ; when 

 the lamps approach the junction of the lines, 

 the rays coming from them represent those 

 of a star falling upon the eye. 



A little consideration wiU make it obvious 

 that this phenomenon does not alter the con- 

 dition of the solar and lunar shadows, by 

 which the distances of these bodies may be 

 ascertained; yet it may be observed that 

 the shadows always imply a lower angle than 

 the bodies appear to make with the horizon, 

 demonstrating the truth of the astronomical 

 fact which I have here endeavoured to ilhxs- 

 trate by a similar, and, as regards its nature, 

 more intelligible, terrestrial phenomenon. 



Beading. J. A. Dayies, 



