108 Progress in Science. [January, 
enters at the bottom, and rising with the A B C mixture, whilst being gently 
stirred overflows by a trough into the settling tanks. The four mixing pits are 
fed by troughs from a crushing mill, in which the ingredients of the A BC 
mixture are pounded up with from 82 to 84 per cent of water. The mixture 
is kept stirred in these pits, and is drawn from them by gravitation into a 
small pumping well, fitted with duplicate earthenware pumps, each capable of 
throwing a quantity of mixture equal to from } to 1} per cent of the sewage 
to a hopper, placed at such a level that it flows thence by gravitation into 
the rising main containing the sewage at the point where it enters the mixing 
cylinder. 10,000 grains of raw sewage are to be mixed with from 10 to 18 
grains of the ABC ingredients, exclusive of water. The compound com- 
prises from 2 to 3 grains of crude sulphate of alumina, 3 grains of animal char- 
coal, ro grains of clay, and a fraction of a grain of blood. Assoon as the mixture 
enters the settling tanks it begins to throw down the precipitate. Each tank 
when full is allowed to remain for six hours, and at the end of that time the 
floor will be covered with a deposit of sewage mud, while all above will be 
clear water. The water will then be run off and passed through filter beds, 
from which it will flow into the river. The mud will then be run off into covered 
acidifying tanks, where, after further settlement, and removal of more water, it 
will be treated with sulphuric acid, in the proportion of.1 pint of acid to a ton 
of mud, in order to fix the ammonia. The mud is then dried on an iron floor 
closely roofed in, the products of combustion from the furnace passing over it, 
and which, together with the steam exhaled by the mud, is passed into a 
vessel or tank, where it is made to pass through water in order to remove any 
noxious properties before escaping into the air. It is computed by the 
company that the 500,000 gallons of sewage to be treated daily at Crossness 
will result in the production of 4 tons of native guano. 
TECHNOLOGY. 
Dr. Jeannel has recorded the results of a series of experiments, from which 
it appears that food, both animal and vegetable, boiled at 95° is more nutritious 
and of better flavour than when boiled at or above 100°. The author illustrates 
this point by referring to the experience gained in mountain localities (every 
Ioo metres’ rise above sea level make a difference of }° C. less in the boiling- 
point of water); as, for instance, at Potosi, at 4061 metres above sea level, 
and an average barometer reading of 454 m.m., the water boils at 86°2°; 
at Mexico, 2277 metres above sea level, 569 m.m. barometer, water boils at 
92°1°; at Briancon, 1321 metres above sea level, 643 m.m. barometer, at 95°4° ; 
these results are also confirmed by the action of the so-called Norwegian 
cooking apparatus. 
The utilisation of crude petroleum for fuel has attraéted the attention of 
many scientific men. The great aim is to discover a process whereby the ten- 
dency to carbonisation should be overcome. This difficulty an American 
inventor has now overcome. From the ‘Chicago Evening Mail,” we learn 
that his apparatus consists of a cylinder, like a small locomotive boiler set on 
end, with a smaller cylinder within it, the intervening space being filled with 
petroleum. The smaller cylinder is filled with six hundred small copper tubes, 
and through these superheated steam passes, producing vapour from the oil 
that fills the interstices between the tubes. This vapourised oil rises through a 
layer of prepared sponge, and just at the point of exit is mixed with super- 
heated steam in any required proportion, thus producing hydrocarbon gas. 
This gas passes through iron tubes to the point where the fuel is needed, and 
is there burned, very much like common gas. In the case shown in illustra- 
tion the kiln was filled with stone, and in a very short time after the fire was 
lighted the heat was more intense than can be expressed by comparison. All 
this time the fire was under perfe@ control, and by a simple turn of a screw 
the combustion was made more or less intense. The experiment was varied 
by admitting a greater or less proportion of steam into the pipes, so that in 
some cases the fire was fed with fifty per cent or more of water, and the 
remainder of vapourised oil. 
