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THE POPULAR SCIENCE MONTHLY 



ing was established in 1873, a system of 

 shop-work in 1876, a laboratory of applied 

 mechanics in 1881, the germ of a biological 

 laboratory was introduced in 1884, and a 

 laboratory for a course of electrical engineer- 

 ing was instituted in 1883. The last study 

 is treated as dependent on mechanical en- 

 gineering, and the recognition of laboratory 

 work in mechanics as an essential feature 

 of a proper training in any branch of the 

 engineering profession is considered the last 

 contribution of the Institute to the philoso- 

 phy of scientific and technical education. 



Petroleum Fuels. Petroleum is defined 

 by Prof. William Robinson as, in the widest 

 sense of the term, comprising not only the 

 mineral oils found in the earth's crust, but 

 also the oils obtained by the destructive dis- 

 tillation of coal and bituminous shale. These 

 complex liquid hydrocarbons vary in ap- 

 pearance from that of clear, light kerosene 

 oils to heavy, dark-greenish slush or semi- 

 fluid slime. After the volatile or lighter 

 oils have been driven off from crude pe- 

 troleum, the heavy oil left is known as 

 residuum in America ; in Russia it is called 

 astatki. This astatki, or heavy petroleum 

 refuse, is an excellent liquid fuel, and is 

 at least twice as good as ordinary coal for 

 steam-raising purposes. The light lubricat- 

 ing oils, intermediate oils, and kerosene or 

 ordinary lamp oils are all being used at the 

 present time instead of coal-gas in the cylin- 

 der of the internal-combustion engine. In 

 some cases the heavier oils are converted 

 into an oil-gas, which, when cooled, is ad- 

 mirably adapted to drive gas-engines. Other 

 internal-combustion engines, as, for instance, 

 the Priestman, Akroyd, and Knight engines, 

 use common burning oils directly, and act 

 as their own gas generators. Prof. Robinson 

 urges that such dangerous and highly vola- 

 tile hydrocarbons as benzoline, gasoline, and 

 petroleum spirit should not be used as fuel 

 in gas-engines. The long series of accidents 

 so frequently attending the use of these 

 light, inflammable vapors have done more 

 than any other one thing to retard the de- 

 velopment of this class of prime motors, by 

 prejudicing the public mind against the ap- 

 pearance of oil in any shape or form. This 

 volatile spirit may, however, act with safety 

 as an evaporating agent instead of steam, as 



in the Yarrow spirit launches, where it is used 

 in the internal parts, and provision is made 

 against leakage, while ordinary burning oil 

 generates the heat. It will thus be seen that 

 liquid hydrocarbons, such as common petro- 

 leum oil, may be employed in prime motors 

 as a substitute for either coal or steam or 

 both. It is becoming generally recognized 

 that for large powers, notwithstanding some 

 advantages, the ordinary vaporizers in petro- 

 leum oil-engines are difficult and trouble- 

 some to work with. In fact, for large en- 

 gines the practical plan obviously is to con- 

 vert oil into gas by means of a gas-producer. 

 Oil-gas, when cooled, can be used with great 

 economy in the engine cylinder. Further, a 

 very decided saving of fuel may be effected 

 by this combination of oil-gas producer with 

 the internal-combustion engine, in place of 

 the boiler and steam-engine, in many places 

 where suitable oil is cheap or plentiful, or 

 where intermittent work is required. On the 

 other hand, more heat may be produced by 

 the direct combustion of liquid fuel with 

 dry steam and air than by converting the 

 oil into gas before using it as a fuel. Oil- 

 gas is a safe, rich, permanent gas made from 

 petroleum oil, and burned with excellent re- 

 sults in the gas-engine cylinder. 



Improved Ventilation. According to 

 Mr. D. G. Hoey, the first attempt to apply 

 really scientific principles to ventilation was 

 made by Sir Humphry Davy in 1811, and 

 nothing better has yet been offered. Davy 

 proposed to ventilate the House of Com- 

 mons by admitting fresh air through numer- 

 ous holes in the floor and carrying off the 

 foul air by tubes in the ceiling leading di- 

 rectly without, heated to promote rapidity 

 of discharge, while the doors and windows 

 were kept closed. The scheme failed in 

 practical application because of defects in 

 mechanism. A method based upon the same 

 principles is proposed by Mr. Hoey, and has 

 been applied in certain buildings in Glasgow. 

 In it, for the admission of the fresh air 

 without currents or draughts, a dado, about 

 three feet high, is fitted at conveniently 

 available parts around the room, with a nar- 

 row space between it and the wall. On the 

 top of it wire gauze or perforated metal is 

 fixed in an inclined position (to keep things 

 from being put upon it). The fresh air is 



