connect isolated facts is much more valuable. Viewed in this light, the study of astronomy will be readily seen to be less efficient for training the mind than the study of physics. Physics, indeed, includes astronomy as one of its parts, but, as the term physics is commonly used, it denotes the science of the changes and conditions of terrestrial matter, and peculiarly of the laws relating to the various emanations of celestial bodies, heat, light, etc. The subjects here referred to are such that their study requires in the very highest degree just those faculties which it is the province of modern education to train. Physics, too, is eminently a practical science; it gives the rationale of what we see all around us, and is, so to say, of progressive difficulty. Its elements may be taught to the young lad, and he may go on for his life in their development. Every special method which is useful educationally, that we have referred to in astronomical study, has its analogue here.
Thermo-dynamics and optics certainly present as wide fields for pure analysis as even celestial mechanics. In the cultivation of the powers of observation, the study of physics stands preeminent; and in the physical laboratory the student has an immense advantage, for in many cases it is within his power to produce by experiment, and on a small scale and under favorable conditions, the same appearances that he observes in Nature. There is thus opened to the mind a vast field for that "scientific use of the imagination" which is so important an element in culture.
Perhaps it is more than time that the exact nature of a physical laboratory or observatory should be explained, and we are fortunate in having a succinct account of its main purpose from the hand of Prof. Henry, of the Smithsonian Institution.
Prof. Henry says (Report, 1870, p. 141) the principal object of a physical observatory is, "to investigate the nature and changes of the constitution of the heavenly bodies; to study the various emanations from these, in comparison with the results of experiments, and to record and investigate the different phenomena which are included under the name of terrestrial physics."
The study of the nature and constitution of the sun, by means of photographs, by experiments on its heat, by the spectroscope, and the comparison of these results with similar observations of the stars, is also pointed out by Prof. Henry, as among the legitimate and necessary works of such an institution as he describes. Climatology, meteorology, magnetics, and electrics, equally belong to its scope.
To completely equip such an observatory as we imagine, would require a great outlay, but, considered only in its relation to a college, an equipment becomes much more simple and less expensive. The apparatus required is simple in its nature, and but few of the single instruments are of great cost, and the true policy of a college would be to allow its laboratory to grow slowly with it, enlarging its scope