Popular Science Monthly 



125 



whatever the source, the light must be very 

 strong. The exposure must be found by 

 experiment, as it varies with the light, size 

 of the lens, the subject photographed and 



The disk for holding the drop of water in 

 lens barrel and the slide holder attachment 



whether or not a color screen is used. The 

 accompanying photographs show the fin- 

 ished instrument and several of its photo- 

 micrographs. 



Very convenient slides may be made by 

 cutting old lantern plates the right size. 

 Colored glass makes very good filters when 

 they are needed. It is of course under- 

 stood that some transparent objects, such 

 as the white blood corpuscles, must be dyed 

 before photographing in order to render 

 them visible. 



The magnification of this instrument 

 ranges from 300 to 500 diameters, depend- 

 ing upon the lens and bellows extension. I 

 have successfully examined and photo- 

 graphed blood corpuscles, the starch cells in 

 a potato and various other things by 

 this method. On one occasion while using 

 a magnification of 923.5 diameters the hair 

 on a fly's leg appeared 2J/2 in- 

 long. Another time, while ex- 

 amining the wing of a recently 

 killed fly I was able to see the 

 watery fluid drying up in the 

 capillaries. To perfect this 



method several different instru- 

 ments were tried out during 

 more than a year of experi- 

 menting. 



The same method of con- 

 structing a lens may be used in 

 a similar manner for an ordinary 

 microscope in cases of emer- 

 gency, but the drop of water 

 will need to be a trifle larger 

 than for the camera lens. It can be made 

 in a small loop twisted on the end of a small 

 wire, allowing sufficient end for a handle. 



An Effective Fireproofing for 

 Children's Clothing 



IT is a common occurrence for children's 

 clothing to take fire from playing with 

 matches and from other causes. This 

 may be prevented by a little precaution 

 which may be taken every time the chil- 

 dren's clothes are washed, particularly the 

 dresses, suits and petticoats. 



A non-inflammable solution of I oz. of 

 alum or sal ammoniac should be added to 

 the rinse water or starch. This renders 

 the garments practically fireproof. Should 

 they take fire, they would burn very slowly 

 and without flame. — Jennie E. McCoy. 



Collecting Ants in a Sponge and 

 Drowning Them 



ANTS in the house or on the lawn can 

 be quickly eradicated in the following 

 way: Wet a large sponge and sift sugar 

 all over it and place in the infested spot. 

 It will be filled with ants in a very short 

 time. Sink it in a pail of water and the 

 ants will leave it and drown. Repeat the 

 operation until they are all destroyed. 



Exterminating Moles and Gophers 

 by Asphyxiation 



IN some of the Western States moles and 

 gophers are a great pest and difficult 

 to exterminate. One of the best methods 

 of getting rid of these animals is to fill their 

 holes with the burnt gases from the ex- 

 haust of a gasoline engine. The illustra- 

 tion shows the method used by a Western 

 farmer for the purpose. He attached a 

 hose to the exhaust of an automobile 



Forcing 

 mobile 



the deadly gases from the exhaust of the auto- 

 engine into the burrows of moles and gophers 



engine and forced the burnt gases into the 

 burrows of the animals, causing death by 

 asphyxiation. 



