MR. WENHAM^S BINOCULAR. 31 



under the eye, and the capability of arresting the incli- 

 nation at that point where the most suitable illumination 

 for the object under examination is obtained, give to the 

 observer powers he has seldom before had at his command 

 in any form of microscope yet produced. 



The horizontal rotation mentioned above allows the object 

 to be directed to the light at every angle in azimuth to 

 borrow a term from the astronomer as the cradle-joint on 

 the top of the pillar gives every angle in altitude ; the 

 object occupying the centre of both motions, by a combina- 

 tion of the two it can of course be placed in every possible 

 position. These angles are read, the latter by a graduated 

 circle in the outer side of the cradle-joint, giving the incli- 

 nation of the body to the vertical, the former by means of 

 the graduated circle at the foot; readings of these circles 

 being taken with the mirror placed as above described at 

 any time by so fixing the instrument that these circles 

 read the same. Any desired effect will be exactly repro- 

 duced, wherever the lamp may be placed a point of the 

 greatest importance to workers with high powers. - 



There is a third divided circle on the substage axis, 

 giving the inclination of the substage to the axis of the 

 body. A strong clamp on the outer side of the cradle-joint 

 holds the body firmly at any inclination, and a graduation 

 on the slide of the coarse adjustment enables the working 

 distance of the objectives to be measured and compared. 



Time alone can show whether these present apparent 

 advantages are lasting, or whether the instrument will wear 

 as well as those of the old form of construction. 



The foregoing illustrations of microscope stands are seen 

 to be both monocular and binocular that is to say, used 

 with one or two eye-pieces. A binocular should always be 

 purchased when the student's means are sufficient, as most 

 objects can be studied with much more ease and comfort 



