792 



SCIENCE 



[N. S. Vol. XLI. No. 10(35 



future are outlined, sueli as the conversion of 

 our national forests into game preserves. It 

 is encouraging to know that there are already 

 three endowments devoted to animal protec- 

 tion, one of $340,000, a second for $51,000 and 

 a third of $5,000. Of course these funds should 

 be greatly increased as the period of relatively 

 easy conquest is now over and the opposition 

 is organized with powerful financial support. 

 This contest is a permanent obligation. 



The two concluding chapters of the volume 

 are contributed by F. 0. Wolcott. One is a 

 valuable summary of the present status of 

 private game preserves, and the other is a very 

 useful bibliography on preserves, protection 

 and the propagation of game. 



With this volume and Hornaday's " Our 

 Vanishing Wild Life" (1913) any intelligent 

 person can become informed upon the present 

 status of this phase of conservation. 



Chas. C. Adams 

 New Yoek State College of Forestry, 

 Syracuse, N. Y. 



an eye screen foe vhe with the microscope 

 Most beginners, as well as many practised 

 observers, usually close one eye when using 

 the microscope. This practise of " squinting " 

 when one is using the microscope for any 

 length of time causes a decided eyestrain. 

 The other alternative of keeping both eyes 

 open requires first of all considerable practise, 

 and if it does not tend to strain the muscles 

 of the eyes, it does give rise to a mental 

 strain, if it may be so expressed; i. e., one has 

 to concentrate his attention constantly on what 

 is seen with the one eye through the mi- 

 croscope, otherwise the objects seen with the 

 other eye will prove very distracting. 



The writer, after having tried many differ- 

 ent shapes and kinds of eye screens, has 

 worked out one that seems to be the most effi- 

 cient. It does away with the eyestrain of 

 both types described above, and is very simple 

 and inexpensive. 



The accompanying sketch shows the outline 

 of the screen. The material from which it is 

 made is a composition called " vulcanized fiber 

 board," 1.5 mm. in thickness and black in 



color. This composition board is very tough 

 and durable. It may be obtained from the 

 Diamond State Fiber Company, EUesmere, 

 N. J. The screen is cut from this board with 

 a knife or with heavy shears. A hole 2.3 mm. 



in diameter (a hair larger than the outside 

 diameter of the standard eyepiece) is bored 

 by means of an extension bit at one end of 

 the screen. The distance from the center of 

 this hole to the middle point of the broad 

 wing of the screen is 8 cm. The extreme 

 length and width of the screen is 12.5 cm. by 

 7.5 cm. 



If the composition board is not available, 

 aluminum 1 mm. thick, painted black or dark 

 green on both sides, will be found a good sub- 

 stitute. 



The eyepiece of the microscope is slipped 

 through the hole in the screen. The sketch 

 shows the eye screen in position for use with 

 the right eye, and to change to the left eye it 

 is a matter of only a few seconds to take the 

 screen from the eyepiece and invert it. 



It will be found that the black surface of 

 the screen is very restful to the eye not in use, 

 and when one alternately uses the right and 

 left eye, it is possible to use the microscope 

 for a much longer period before the eyes be- 

 come tired than without the eye screen. 



Orton L. Clark 



Mass. Agr. Experiment Station, 

 Amherst, Mass. 



exhibition op the royal photographic 



SOCIETY 



To the Editor of Science : The Eoyal Pho- 

 tographic Society of Great Britain is holding 

 its sixtieth annual exhibition in August and 

 September of this year. This is the most rep- 

 resentative exhibition of photographic work 



