558 



Journal of Applied Microscopy. 



vation than a confusion of lights reflected from half a hundred polished surfaces, 

 supplemented by a general glare from wall, ceiling, and floor. One needs only 

 to protect the eyes for a short time from all light except that coming through the 

 ocular in order to prove the facts stated. With the eyes shaded it will be found 

 that very much less illumination will be required, while at the same time 

 definition of a much higher order will be secured. 



To profit by these obvious advantages, the writer adopted the simple device 

 of wearing an eye-shade to which had been fastened a square of black cloth at 

 the upper edge. This cloth is of such a length that when the lower edge is 

 gathered around the top of the microscope tube and the shade adjusted on the 

 head, the eye will be about low enough for observation. The cloth falls against 

 the face and around the eyes so that all light except that coming from the object 

 is prevented from entering. Thus protected, the eyes can be used continuously 

 for hours without becoming fatigued, and the vision is clear and distinct. I 

 believe that no one who has once employed some such means of protecting the 

 eyes will ever conduct further serious observations without thus conserving his 

 eyesight. C. E. McClung. 



University of Kansas. 



An Adjustable Dissecting Microscope. 



The accompanying photograph shows two dissecting microscopes, both of 

 the same pattern. Each is provided with two racks and pinions ; one for 

 adjusting the lens, the other, lower one, for raising and lowering the mirror, 

 stage, and lens. 



In the one shown at the left, the lens when in focus is 260 mm, from the 

 table, about the average height of compound microscopes. In the one shown 



at the right, the lens is 350 mm. from 

 the table. The lower rack and pinion 

 permits of all intermediate heights 

 according to the needs of the operator. 

 The instrument weighs four pounds 

 and five ounces, which is sufiicient to 

 give it stability, even when racked up 

 to the highest point, and has nickel 

 finish, giving it a fine appearance 

 which is in no way a deception. 



The idea of having a dissecting 

 microscope of this kind was suggested 

 to me from having been obliged to 

 either double myself into a position 

 to see an object through the common 

 makes of low dissecting microscopes, 

 or being obliged to place them on 

 temporary supports which generally 

 proved unsteady. With this instrument one can work for a long time comfort- 

 ably, because he is in a comfortable position, and his arms and hands take a 

 natural position. 



