A further advantage peculiar to this microscope is, that by it the outlines of every object may be taken, even by those who are not accustomed to draw; while those who can draw well, will receive great assistance, and execute their work with more accuracy, and in less time than they would otherwise have been able to have performed it in. Most of the designs for this work were taken with the lucernal microscope; and I hope the accuracy with which they are executed, will be deemed a sufficient testimony in favour of the instrument. In this point of view it will, I think, be found of great use to the anatomist, the botanist, the entomologist, &c. as it will enable them not only to investigate the object of their researches, but to convey to others accurate delineations of the subject they wish to describe. By the addition of a tin lanthorn, transparent objects may be shewn on a screen, as by the solar microscope. Transparent objects may be examined with this instrument in three or four different modes; from a blaze of light almost too great for the eye to bear, to that which is perfectly easy to it. When this instrument is fitted up in the best way, it is generally accompanied with a small double and single microscope. Fig. 1. Plate III. represents the IMPROVED LUCERNAL MICROSCOPE, mounted to view opake objects; A B C D E is a large mahogany pyramidical box, about fourteen inches long, and six inches square at its larger end, which forms the body of the microscope; it is supported firmly on the brass pillar F G, by means of the socket H, and the curved piece I K. L M N is a guide for the eye, in order to direct it in the axis of the lenses; it consists of two brass tubes, one sliding within the other, and a vertical flat piece, at the top of which is the hole for the eye. The outer tube is seen at M N, the vertical piece is represented at L M. The inner tube may be pulled out, or pushed in, to adjust it to the focus of the glasses. The vertical piece may be raised or depressed, that the hole, through which the object is to be viewed, may coincide with the center of the field of view; it is fixed by a milled screw at M, which could not be shewn in this figure. At N is a dove-tailed piece of brass, made to receive the dove-tail at the end of the tubes M N, by which it is affixed to the wooden box A B C D E. The tubes M N may be removed from this box occasionally, for the convenience of packing it up in a less compass. O P a small tube on which the magnifiers are screwed. O one of the magnifiers; it is screwed into the end of a tube, which slides within the tube P; the tube P may be unscrewed occasionally from the wooden body. Q R S T V X a long square bar, which passes through the sockets Y Z, and carries the stage or frame that holds the objects; this bar may be moved backward or forward, in order to adjust it to the focus, by means of the pinion which is at a.