And so I might proceed until I had wearied you with illustrations showing what can be done with telescopes so small that they may fairly be classed as "common," Webb says that such apertures, with somewhat high powers, will reveal stars down to the eleventh magnitude. The interesting celestial objects more conspicuous than stars of that magnitude are sufficiently numerous to exhaust much more time than any amateur can give to observing. Indeed, the lot of the amateur is a happy one. With a good, though small, telescope, he may have for subjects of investigation the sun with his spots, his faculae, his prominences and spectra; the moon, a most superb object in nearly every optical instrument, with her mountains, valleys, seas, craters, cones, and ever-changing aspects renewed every month, her occupations of stars, her eclipses, and all that; the planets, some with phases, and other with markings, belts, rings, and moons with scores of occupations, eclipses and transits due to their easily observed rotation around their primaries; the nebulae, the double, triple and multiple stars with sometimes beautifully contrasted colors, and a thousand and one other means of amusing and instructing himself. Nature has opened in the heavens as interesting a volume as she has opened on the earth, and with but little trouble any one may learn to read in it. I trust it has been shown that expensive telescopes are not necessarily required for practical work. My advice to an intending purchaser would be to put into the objective for a refractor, or into the mirror for a reflector, all the money he feels warranted in spending, leaving the mounting to be done in the cheapest possible manner consistent with accuracy of adjustment, because it is in the objective or in the mirror that the _value_ of the telescope alone resides. In the shops may be found many telescopes gorgeous in polished tubes and brass mountings which, for effective work, are absolutely worthless. On this subject, I consulted the most eminent of all discoverers of double stars, an observer who, even as an amateur, made a glorious reputation by the work done with a six inch telescope. I refer to Mr. S.W. Burnham, of the Lick Observatory, who, in reply, kindly wrote: "You will certainly have no difficulty in making out a strong case in favor of the use of small telescopes in many departments of important astronomical work. Most of the early telescopic work was done with instruments which would now be considered as inferior to modern instruments, in quality as well as in size. You are doubtless familiar with much of the amateur work, in this country and elsewhere, done with comparatively small apertures. _The most important condition is to have the refractor_, whatever its size may be, _of the highest optical perfection_, and then the rest will depend on the zeal and industry of the observer." The italics are mine.