442 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the scale exactly coincide with two consecutive divisions of the 

 wheel. The half millimetres of the wheel can then be read to 

 l/60ths(=0-01 mm.). 



As the plant grows the wheel revolves, and the extent of the 

 revolution is read on the wheel and scale by the aid of the Microscope. 

 If the weight reaches the table, the movable pillar can be drawn out, 

 and when the divisions on the 10 cm. of the wheel are passed over 

 it can be brought back to again by gently raising the weight. 



Tetlow's Toilet-bottle Microscope.* — D. Tetlow has patented the 

 following instrument, the specification of which we give verbatim 

 without any attempt at an abstract, venturing only to emphasize one 

 paragraph by italics of our own. The figures are also facsimile. 



" To all whom it may concern : Be it known that I Daniel Tetlow, 

 of the city and county of Philadelphia, and State of Pennsylvania, 

 have invented a new and useful Improvement in Microscopes, which 

 improvement is fully set forth in the following specification and 

 accompanying drawings, in which — 



Fig. 57 is a perspective view of a Microscope embodying my 

 invention with central vertical sections thereof in line x x. 



My invention consists of a Microscope having a body of the 

 form of a bottle and the eye-piece removably fitted to the neck thereof, 

 the construction, operation, and advantages being hereinafter set 

 forth. 



Referring to the drawings, A represents the body of a Micro- 

 scope, the same being essentially of the form of a glass bottle 

 having a closed bottom which is integral with the body; and B 

 represents the eye-piece, consisting of the lens or glass C and metallic 

 cap or holder D, the lens being properly set in the holder, and the 

 latter removably fitted on the neck of the bottle. 



E represents a base on which the bottle is stood, the same being 

 formed of metal and receiving the bottom of the bottle, said bottom 

 being shouldered, so as to properly set in the base and provide a neat 

 joint for the parts. 



While I have described the holder D and base E as metallic, 

 sheet metal being preferred, it is evident that they may be formed of 

 any suitable material and the base may be part of the glass. 



The eye-piece is removed and an object to be examined placed 

 in the bottle. The eye-piece is then restored, and the object may 

 then be viewed through the lens C, as in Microscopes. 



The body, being of the form of a bottle, has the following advan- 

 tages : The object is not liable to be lost or displaced. It may be 

 seen through the wall of the body and comparisons readily made as 

 to its natural and magnified conditions and remain in the body for 

 further examination, as the bottle provides an inclosure, the access 

 to which being the mouth of the bottle, and this is covered by the 

 lens C. 



Another object of the invention is to employ the body A, primarily, 



* Specification forming part of U.S.A. Letters Patent No. 287,978, dated 

 November 6, 1883. Application filed August 24, 1883. 



