42 



C. M. BREDER, JR. 



economical only where water saving has 

 no significance. 



The water flowing into this aquarium is 

 controlled by a float valve constructed of 

 a glass stopcock, a suitable-sized chemical 

 flask, and some small parts of either wood 

 or plastic. These are assembled as shown 

 in figure 3 and are held together by iron 

 screws and two pieces of strip steel. This 

 metal is mentioned because of the danger 

 of toxic !=alts forming if brass were used, 

 since such corrosion might fall into the 

 aquarium. A 1-hole cork is bolted to a 

 piece of Incite and then inserted into the 

 mouth of the flask as shown. A dowel or 

 plastic rod is inserted in the other hole 

 in the plastic piece and secured. A sim- 

 ilar piece of plastic is movably secured on 

 this rod and on a similar one at right 

 angles to it, extending from the valve. 

 This is so arranged that the center of the 

 flask comes to rest directly below the hori- 

 zontal rod extending from the valve. This 

 is best seen in tlie plan view of the device. 

 By loosening the two setscrews in the 

 upper plastic piece the flask may be moved 

 vertically on the one and horizontally on 

 the other. Figure 4 shows one arrange- 

 ment of this device. 



The extending glass tubes which are an 

 integral part of the stopcock are inserted 

 through two snug holes in tlie wood or 

 plastic endpieces of the valve, and these 

 are held in position by the two steel strips 

 which are held in place by four wood 

 screws. In the center of one of these steel 

 pieces a hole is tapped into which is 

 screwed a setscrew with a pointed end 

 (about 60°) and a locknut as shown. The 

 stem handle of the stopcock is imbedded 

 in a piece of wood cut about as shown. 

 For this purpose a suitable space is hol- 

 lowed out in the block into which the stem 

 is inserted, the space around being filled 

 with plastic wood or a similar product. 

 The face of the block and the stopcock 

 stem must be at right angles. On the outer 



face of the block a small steel strip is af- 

 fixed with a small drill-tip impression at 

 its center on the axis of the stem. Into 

 this the pointed setscrew fits as shown. 

 This is adjusted so that the valve works 

 freely without being too tight or leaking. 

 This prevents the glass stopcock from 

 working loose and leaking after long- 

 continued operation. The diagonal dotted 

 line on the block indicates the position of 

 the hole through the plug as well as that 

 of the liandle on the stem. It is shown 

 in a position just fully closed. It is obvi- 

 ous that with a fall in the water level the 

 valve will open proportionally to the 

 change in water level and shut itself off 

 as the water level rises. 



The interaction between the constant- 

 level siphon and this valve is indicated in 

 figure 5. It is clear that danger from 

 flooding could come only from some dam- 

 age to the equipment. If, for instance, 

 something clogs the overflow in any way, 

 the float valve shuts itself off when it has 

 reached the predetermined point for 

 which it has been set. 



As an extreme point of precaution a 

 safety alarm or shutoff could be built as 

 an entirely separate system. Such a de- 

 vice, which has never failed so far as the 

 writer's experience goes, consisted of an 

 old pair of contacts such as are to be found 

 on relays, to one member of which was 

 fastened a shell vial. This huns: over the 

 water in such a manner that when the 

 water rose over a specified place it lifted 

 the vial and pushed the two contacts to- 

 gether. It operated on two dry cells to 

 ring a doorbell but could be used with a 

 relay to sw^itch on house current to operate 

 any suitable device. This could be a nor- 

 mally open solenoid valve placed in the 

 supply line. Such extreme caution would 

 only be warranted where a little flooding 

 would be disastrous. 



It is obvious that this float valve could 

 be used under certain experimental pro- 



