Such learned nonsense is a disgrace to our species, and to the rational faculties with which man is endowed, and exhibits, in a most ludicrous manner, the imbecility and prejudice of those who made bold pretensions to erudition and philosophy. The statement of such facts, however, may be instructive, if they tend to guard us against those prejudices and pre-conceived opinions, which prevent the mind from the cordial reception of truth, and from the admission of improvements in society which run counter to long-established customs. For the same principles and prejudices, though in a different form, still operate in society and retard the improvement of the social state, the march of science, and the progress of Christianity. How ridiculous is it for a man, calling himself a philosopher, to be afraid to look through a glass to an existing object in the heavens, lest it should endanger his previous opinions! And how foolish is it to resist any improvement or reformation in society, because it does not exactly accord with existing opinions, and with ‘the wisdom of our ancestors.’ It is not a little surprising, that Galileo should have first hit on that construction of a telescope which goes by his name, and which was formed with a _concave_ glass next the eye. This construction of a telescope is more difficult to be understood, in theory, than one which is composed solely of convex glasses; and its field of view is comparatively very small, so that it is almost useless when attempted to be made of a great length. In the present day, we cannot help wondering that Galileo and other astronomers, should have made such discoveries as they did with such an instrument, the use of which must have required a great degree of patience and address. Galileo’s best telescope, which he constructed ‘with great trouble and expense,’ magnified the diameters of objects only thirty-three times; but its length is not stated--which would depend upon the focal distance of the concave eye-glass. If the eye-glass was two inches focus, the length of the instrument would be five feet four inches; if it was only one inch, the length would be two feet eight inches, which is the least we can allow to it--the object-glass being thirty-three inches focus, and the eye-glass placed an inch within this focus. With this telescope, Galileo discovered the satellites of Jupiter, the crescent of Venus, and the other celestial objects to which we have already alluded. The telescopes made in Holland, are supposed to have been constructed solely of _convex_ glasses, on the principle of the astronomical telescope; and, if so, Galileo’s telescope was in reality a new invention.