84 Modern Microscopy 



ordinary way is inverted, that is, the object is seen upside 

 down. A very good form of binocular microscope, devised 

 by Stephenson and made by Swift and Son, erects the image, 

 or, in other words, enables it to be seen the right way 

 up. It is excellent for dissecting purposes, and high powers 

 can be employed with it ; still, it cannot be described as an 

 all-round microscope, and would have to be classed with in- 

 struments for special work. Our advice on the question of 

 a monocular or binocular microscope is : If the instrument 

 be required for strictly educational, scientific, or photo- 

 graphic work, the monocular must be chosen. The bulk 

 of the general amateur's work is done with comparatively 

 low powers, and in such cases the binocular is unquestion- 

 ably of advantage, and to be preferred. If it is proposed 

 to combine scientific with general work, a good plan is to 

 have two separate bodies monocular and binocular inter- 

 changeable in the same bearings. The maximum facility 

 is then at the disposal of the user. It should be noted that 

 when the two bodies are chosen, it is well to have centring 

 screws to the rotating stage, as described page 13, because 

 the bodies rarely have identically the same centres, and the 

 stage could not otherwise be made to rotate concentrically 

 with both bodies. 



MICROSCOPES FOR SPECIAL PURPOSES. 



Dissecting Microscopes. The dissecting microscope 

 is usually, so far as the stand itself is concerned, of plain, 

 but substantial construction. It should have a good clear 

 stage, preferably consisting of a glass plate, which can be 

 interchanged with opal, glass, ebonite, etc., substantial 

 supports for the hands ; rack-work and pinion to focus the 

 magnifying-lens ; and a gymbal, carrying a mirror on one 

 side and a mat opal disc on the other. In this department 

 Continental manufactures may be considered superior to 

 the English on account of their variety of design, sub- 

 stantial and excellent construction, and economy in price. 



