There are six magnifying lenses contained in a brass wheel screwed in a circular brass box P; this wheel is moveable about its center with the finger, and stops by a click when the magnifiers are each centrally under the body A B above, or the hole in the arm C D. They are marked from No. 1, to 6, and the proper number shewn in a small opening made in the side of the brass box. This wheel P screws into the arm C D, and may occasionally be taken off to admit of the silver speculum, or a single magnifier, hereafter to be described. There is a small line cut on the edge of the arm C D, which must be brought to the right hand edge of its socket, in order to center the magnifier to the body and the stage. By unscrewing the body A B, the single magnifiers in the wheel P being then only left, the instrument readily forms a single microscope. A small pocket hand single or opake microscope may easily be extracted from this apparatus. When the body A B is screwed off, and the arm C D slipt away from its frame with the wheel of magnifiers, and the forceps, wire, and joint _b_ applied to it, by a hole made in the arm for that purpose, as represented at V, it is then ready for the examination of any small object that may present itself in the garden, &c. and will be found very convenient whenever the whole instrument is not required. LIST OF APPARATUS GENERALLY MADE TO THIS MICROSCOPE. The wheel, with the magnifiers, P. Fig. 1. The body of the microscope, A B. The slider-holder, K. The tube, with the condensing lens L, to be used by candle-light. The pin and arm _a_, either for the above lens, or for the silver concave speculum _e_. The silver concave speculum _e_, fitted to the arm above, and used common to all the magnifiers in the wheel and body A B, it is to reflect the light from the concave or plane mirror O below, upon the opake objects, then called the compound opake microscope. A silver concave speculum _f_, with a single magnifier; it screws to the under part of the arm C D in room of the wheel of magnifiers, and forms then the single opake microscope. A brass cone _g_, to place under the stage N I S, and serves to diminish the reflected light when necessary. The jointed nippers _b_, fitted to the stage, to hold any small insect, or other opake object. A cylinder of ivory _h_, to fix on the pointed end of the nippers, black on one side and white on the other, to make a contrast to the opake object used.