20 



THE GUIDE TO NATURE. 



are one and one-half by forty-three 

 inches ; the length thirty-two inches 

 and the breadth eighteen inches. The 

 framing' is comparatively simple yet 

 strong"; all the end and side rails being 

 halved, glued and screwed together 

 vvilh two number nine, one-half 

 inch screws, inserted from each direction. 

 A projection the width of the corner post 

 is allowed at each corner on both the 

 end and side rails. These projections 

 are in turn mortised into the corner 

 post and secured with glue and two 

 other screws inserted into the post 

 from the opposite direction. There- 

 fore, each corner is secured with glue 

 and four screws, making a joint of 

 great strength. The top and middle 

 rails and the posts between these points 

 are grooved for the reception of the 

 glass. The bottom of the aquarium is 

 made of seven-eight inch wood and is 

 supported by four cross pieces beneath, 

 giving a firm foundation for the weight 

 it has to sustain. 



The manner of cementing and set- 

 ting the glass is identical with the pro- 

 cess when metal frames are emuloyed. 

 After the side and end pieces of glass 

 are nlaced in position, a piece of olate 

 glass is set into the bottom, thus lock- 

 ing the four side pieces into position 

 and keeping the water from coming 

 into contact with the frame at any 

 point. 



The soace between the middle and 

 bottom frames under the aquarium 

 proper may be enclosed and fitted with 

 doors to serve as a cabinet for foods, 

 utensils, etc ; or it may be left open or 

 fitted with a shelf. 



The style of finish may be deter- 

 mined by the nature of the wood and 

 the furniture it is desired to match. 

 Aquaria so constructed are strong and 

 have been satisfactory to the writer 

 in every way. One, of the above di- 

 mensions, will hold about thirty-three 

 gallons of water, which means a weight 

 of about two hundred and seventy-five 

 pounds, not including about fifty pounds 

 of sand and pebbles, having a pressure 

 on the bottom of about seven and three 

 quarters pounds per square inch. It 

 will probably take a little longer time to 

 make an aquarium with a wooden than 



with a metal frame, but it is just as easily 

 constructed and the finished product, 

 from an artistic point of view, is far 

 superior to the metal forms usually to 

 be had at the aquarium dealers' shops. 

 In every way it is a beautiful house- 

 hold ornament, a constantly varying 

 animated picture, in an appropriate, 

 handsome and artistic frame. 



At Cold Spring Harbor, Long Island. 



The annual announcement of the 

 summer session of the Biological 

 Laboratory has just been received. It 

 calls attention to the excellent Board 

 of instruction and the facilities for 

 studying plant and animal life. 



The real student of nature, especial- 

 ly from a technical point of view, will 

 find the Laboratory a good place at 

 which to spend a vacation. For fur- 

 ther particulars, address Dr. Charles 

 B. Davenport, Cold Spring Harbor, 

 Long Island, New York. 



Lack of Knowledge of Common Things. 



The following letter has been re- 

 ceived : 



"A strange animal has made its ap- 

 pearance in the Department of 



the City Hall. The head of the Bureau 

 thinks a large spider has changed by 

 metamorphosis into a large green 

 moth. I know this to be impossible, 

 but I am anxious that an expert shall 

 investigate the matter, as I am no au- 

 thority on such subjects. The moth 

 is undoubtedly a very strange one, and 

 is entirely unfamiliar to me. 



"If you can call and look at it, I 

 think you will be interested." 



There are so many things to know 

 these days that considerable discrimi- 

 nation should be used in making a se- 

 lection for school children. They are 

 probably taught some things less use- 

 ful than an elementary knowledge of 

 Entomology and other branches of na- 

 tural history. There may be some 

 excuse for the grown people of to-day 

 who know nothing about the trans- 

 formation of insects, but the children 

 of the present time should be better 

 taught. The large spider mentioned 

 in the letter was Arglope riparia and 

 the moth PJwlus pandoras. — Entomolo- 

 gical N^ezvs. 



