1204 Journal of Applied Microscopy 



tain what sized plate will cover it with the least waste. It also shows at a glance 

 how much the object will be reduced or enlarged for that particular plate, and 

 by reading the rule the camera may be adjusted at once. (2) The card being 

 placed imder the glass plate shows the exact field that the object should occupy 

 to be included on the ground glass. 



(3) A Glass Plate. A method for posing insects, and one equally serviceable 

 for arranging flowers, is to secure a clean glass plate, such as the glass from a 

 photographic plate or other equally good sheet of glass of the desired size. The 

 object is arranged upon this glass and when properly posed is slipped into posi- 

 tion under the lens. The glass being clean, the plate of the stand likewise, and 

 both free from defects, no image of either will be formed on the sensitive plate. 

 This method was developed by Prof. A. L. Quaintance while associated with the 

 writer. 



(4) A Paper Rule such as is sold by the Cambridge Botanical Supply Company, 

 with sharp lines upon clear white paper, a little heavier than heavy herbarium 

 paper, makes a convenient object to focus upon. Such a rule is so light that it 

 may be placed upon the object to be photographed for the purpose of verifying 

 the focus before inserting the plate-holder. In many cases the rule may be left 

 in an appropriate portion of the field to serve as an index of the enlargement or 

 reduction. In the absence of a light paper rule, a visiting card, as Mr. McFar- 

 land suggests, makes a convenient object to prove the focus. A wooden rule is 

 anything but a desirable substitute. 



In conclusion I would recommend heavier angle-iron for the frame, say about 

 2^ or 3 inches. The one-inch makes a frame appear light and the post not so 

 firm as might be desired. In practice it has given no trouble. 



A suitable background is supplied in the same way as suggested in the book- 

 let referred to before. P. H. Rolfs, Botanist. 

 Clemson Agricultural College, Clemson College, S. C. 



Received for Notice. 



Modern Photography in Theory and Practice. '^'^is book is, as its title page states, 



H. S. Abbott, Chicago; Geo. K. Hazlett & "A Hand Book for Amateurs," con- 



' taining chapters on the principal forms 



of cameras and apparatus likely to be used by the amateur, methods of loading 



plate-holders, recording exposures, focusing, exposing, development, and the 



various processes in the manipulation of the negative, paper, etc., to produce a 



satisfactory print. Standard formulae for the various solutions are freely quoted, 



and numerous illustrations show the principal kinds of paper for making prints. 



The book is intended for the studious amateur, and as a repository of useful 



formula; and hints for the beginner it serves its purpose admirably. 



L. B. E. 



