110 H. J. FASE ON A PORTABLE BINOCULAR 



and combs. I therefore sought some arrangement by which all the 

 things required for 



1. Dissecting. 



2. Mounting, and 



3. A binocular for observing could be carried in a compact form. 

 Although fairly well acquainted with various adaptations and 



forms of instrument already made, I did not find what I wanted. 

 I therefore set to work to make a model in wood, which should 

 meet the following requirements, viz., that it should contain 



I. A full-sized, steady dissecting stage, with absolutely neces- 

 sary instruments. 



Two pairs scissors, knives. 



Two pairs forceps, watch-glass, needle points, &c, &c. 



II. An arm, so constructed that it would carry — 



1. A large low-power lens for dissecting. 



2. A ring, into which various objectives could be dropped for 

 the same purpose. 



3. A binocular body, which could be easily substituted for the 

 ring, and 



(a) Permit of investigation of the manner in which the dissection 

 was progressing, and also 



(£) Be steady enough to make an efficient binocular for ordinary 

 observation. 



III. That there should be places in the case for a small number of 



1. Cements, and media most usually required by working 

 microscopists. 



2. Brushes, dipping tubes, lamp clips, slides, glass circles, 

 troughs, a hot plate, turn-table, packed in such a way that each of 

 them should be safely carried, easily got at, and replaced. 



3. That every fitting should be full-sized. 



The model I made in wood — many thanks are due to Mr. Swift, 

 who has most patiently rendered it into that, in which, modest man 

 though he be, he confessedly excels, viz., brass. 



A view of the arrangement will make the plan clearer than any 

 description can do. But I will call attention to one or two points 

 which might escape notice on a first inspection. 



1. The condenser is formed of two lenses, and besides acting as 

 an ordinary condenser, makes a capital long focus dissecting lens. 



2. The mirror is removable, and can be utilized as a side re- 

 flector above the stage. 



