Like its sister instrument, the micro-telescope consists of an ordinary microscope to which is attached a specially designed object glass in a tube, which take the place of the condenser. The makers, indeed, provide two of these object glasses--one for viewing objects from one to two feet away, the other for viewing objects from a distance of three feet to the planets, if need be. Once when the instrument was being tested some crumbs were placed on the floor at a distance of four yards and strongly illuminated, and the microscope with a 1-inch objective focussed on the crumbs. With this objective in an ordinary microscope the magnification would be about thirty diameters. Presently some mice came out, and made themselves at home with the crumbs. The mice could be examined at this distance, without their being aware of it, so well that individual hairs were easily visible and about half a mouse was in the field of view. In point of size each mouse appeared about the same as a beaver within a foot or two. Messrs F. Davidson & Co., 29 Great Portland Street, London, are well known for the high state of perfection to which they have brought the micro-telescope and other instruments connected with microscopy. The novelty of the micro-telescope will appeal strongly to the Nature lover. At a distance of a few feet a spider can be magnified to the size of a large cat, and it can be watched spinning its web with spinnerettes the size of teacups. Ants at a distance of six feet are seen to be fearsome individuals, six inches in length, and their tiny burdens are so magnified that they appear like yule logs or goodly-proportioned boulders, according to their nature. At a distance of ten feet a wasp may be seen scraping tiny shavings of wood from oak palings by means of its jaws--shavings which it converts into paper for building its nest. Very small insects may be observed as they come into the world from their chrysalis stage. The never-tiring jaws of the caterpillar may be seen at work devouring some favourite leaf--the whole action of biting and swallowing the vegetable matter can be plainly seen. Such interesting events as the tending of green flies by ants, the leaf-cutting habits of the leaf-cutter bee, and a hundred and one other events are all revealed by the micro-telescope and at such a distance that the living objects are not disturbed in their activities, being quite unaware that they are under observation. To the botanist the instrument is no less useful.