336 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1936 



is not available. The highly inflammable nature of kerosene and 

 gasoline, and the danger of handling it in filling the stove, besides 

 the difficulty of keeping it from leaking onto the outside of the tank, 

 has resulted in countless explosions, fires, and deaths in rural com- 

 munities and even in cities, where such fuel also finds considerable 

 use. How simply this danger may be obviated by filling the tank 

 with very porous diatomaceous earth, without greatly reducing its 

 holding capacity for gasoline, is illustrated in this man's invention. 



Tanks filled with diatomaceous earth, saturated with gasoline, will 

 contain a volume of gasoline over three-quarters their actual outside 

 volume. They can be put up at the factory to be sold in any grocery 

 or hardware store, or simply to be exchanged at the price of the gaso- 

 line for tanks recently emptied, doing away with the necessity of 

 handling the fluid at all. The tank is slipped into the stove and 

 coupled by a simple connection to the pipe leading to the burners. 

 Pushing the tank into the stove makes an electrical connection which 

 lights a small electric bulb fitting into a depression in the outside 

 of the tank. The warmth from this little light expands and volatilizes 

 some of the gasoline, producing a pressure within the tank of 8 

 pounds. When this pressure is reached, a simple automatic pres- 

 sure regulator breaks the electrical contact, turning off the light, 

 and the warming and volatilization is stopped until the pressure again 

 drops slightly and the light once more comes on. When a burner is 

 turned on, the volatilized gas flows to the burner and is ignited. The 

 resulting drop in pressure causes the light to turn on and drive more 

 gasoline out of the diatomaceous earth in the tank. The w^iole ap- 

 paratus resembles the ordinary gas stove, and the danger of handling 

 liquid fuel is avoided, as it is to all intents and purposes in a solid 

 state and hence cannot leak or spill out if the tank is upset or 

 damaged. 



Not only do the little shells make a good absorbent, but they are an 

 equally good filter material, owing to the porous structure as seen 

 in some of the photographs (pis. 13-19). In sugar refineries, if the 

 sugar solution is run through cloth or fiber filters, the sediment soon 

 collects on the filter surface, clogging it up and stopping the process. 

 If a certain quantity of finely divided diatomite, consisting of the 

 loose shells of diatoms, is dumped into the solution to serve as an 

 aid to filtration, or technically, a "filter-aid", some of these little 

 shells soon pile up against the cloth and their fine pores catch the 

 sediment, then more shells fall against them and more sediment is 

 held in these, and so on. At no time is there a thick impervious mat 

 of sediment on the filter, but a porous mass of diatom shells and 

 sediment intermixed, so that a continuous filter surface is being 

 formed during the process of filtration. There is no other substance 

 which meets the requirements for this need. 



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