The Microscope. 



diaphragm is an important part of the stand, as it is 

 very often necessary to cut off some of the rays of 

 light to get the best effect with high powers ; and for 

 this purpose the tubular diaphragm which is slipped 

 into a fitting under the stage, is the best; it has a 

 very small hole, and can be removed altogether when 

 using a low power ; a good plan is to have no fixed dia- 

 phragm at all, but a small piece of metal with a milli- 

 metre hole in the centre, made so that it can be slipped 

 into the hole in the stage from above, where it will lay 

 flush with the glass plate. It must be carefully cen- 

 tred with the tube. 



Having selected a maker, the student should get him 

 to explain the working of the different parts, as all that 

 is necessary for a beginner can be learnt in ten minutes 

 in that way. 



This small student's stand is all that will be required 

 by the student for a long time, as with it high powers 

 can be used and whatever work may be done in the 

 future, it will always be the working stand. 



Good students' microscopes are made by Mr. Crouch, 

 66 Barbican; Messrs. Swift and Son, University Street. 



The Object Glass. The object glass or objective, is 

 the most important part of the microscope, and it is 

 necessary to have good glasses to do satisfactory work. 



The most useful for the student are the f or |- for a 

 low power, and the J, 1, or ^ for a high power ; with 

 a f and ^ the student can do all the requisite work for 

 a long time, and then with the addition of a J, and oil 

 immersion ^ he would be set up for life. 



The student should get some good microscopist to 

 test the object glasses for him before purchasing them, 



