372 Portable Instrument for acquiring 



contemplation of which fills the soul with reverence and affec- 

 tion for the great Author of nature, and banishes all narrow 

 and superstitious notions respecting him. 



The cultivation of this science, therefore, cannot be too 

 strongly recommended to the attention of young people. The 

 eager curiosity and avidity for discovery which so peculiarly 

 distinguish that period of life, when the reasoning faculties 

 begin to develope, is peculiarly fitted for its reception — and, 

 accordingly, amongst the better-educated classes of society, 

 the elements of this science are generally considered as a ne- 

 cessary branch of instruction — though commonly fimited to a 

 mere dogmatic explanation of the Copernican system, and the 

 use of the globes. 



But this superficial mode of instruction, though sufficient to 

 enable any one to understand the real motions of our planetary 

 system, and explain the apparent motions which must result 

 from them, is hardly sufficient to satisfy inquisitive reasoning 

 minds, since it leaves them ignorant of the means by which the 

 distances, magnitudes, and orbits of the planets and comets 

 were first discovered ; and how, if lost, a knowledge of them 

 might be recovered from observations alone. 



The most pleasing methods of instruction will generally be 

 found the most efficient. It is impossible for any one who has 

 had the least experience in teaching not to have perceived, 

 that one practical application of science makes a deeper and 

 more lasting impression on the mind of a learner than a 

 thousand theoretic propositions. 



An accurate knowledge of the fixed stars is the first step 

 to practical astronomy ; it is, in fact, the alphabet of the 

 science. By the rising, southing, and setting of these bodies, 

 astronomers are enabled correctly to measure time ; and from 

 their apparent altitudes, to determine the latitude of places on 

 the surface of the globe, whilst the permanent situations which 

 they maintain with respect to one another, furnish them with 

 so many marks by which to trace the course of the sun, moon, 

 and planets through the heavens. Such were the data which 

 enabled Copernicus and Newton to unravel the seeming irre- 

 gularity of their apparent paths, and explain the beautiful sim- 

 plicity of their real motions. 



The instruments usually had recourse to for this purpose 



