Page:Popular Science Monthly Volume 88.djvu/441

 Popular Science Monthly

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��From the portrait by S. J. \Vi:

��extent, but the weight of the cotton is considerably increased.

The oxygen which the cotton al)sorbs from the nitric acid is sufficient to con- sume all of the cotton without atmo- spheric air, so that when guncotton is put in a confined space and set on fire it explodes with great vio- 1 e n c e, producing what are called carbon dioxide and carbon monoxide, with free nitrogen and steam.

When the cotton is immersed in the nitric acid the acid takes water out of the cotton, which dilutes the acid. But the cotton gets the best of the bargain, because the weight of oxy- gen and nitrogen which the cotton receives is in ex- cess of the weight given up by the cotton.

In order to keep the nitric acid bath strong enough to act on the cotton, and to minimize the acid, it is nec- essary to add sul- phuric acid to ab- sorb the water, anrl it takes about three parts sul- phuric acid to one part of nitric acid to make a proper mixture for this purpose. The sul- phuric acid, how- ever, has no eft'ect whatsoever u p o n the cotton. It merely acts to absorb the water liberated from the cotton.

There are several ways in which the cotton is treated with the acid mixture. The oldest and simplest was merely

���If you loant to know Jiow to write poetry or blast a subway, lay out a garden or design a battleship, ask Hudson Maxim. It is no off-hand slap dash opinion that he will give, but a ivell reasoned statement. For Maxim believes that everything could be reduced to a science, whether it is writing sonnets to your lady's eyebrow or defending the country against foreign invasion.

But ^laxim is above all an authority on explosives. That is why we asked him to write this article for the Popular Science Monthly. He invented the process of mak- ing the multi-perforated smokeless powder used by the United States. His Maximite, adopted by the United States Government, was the first high explosive which could be sent through armor plate and burst inside of a ship. That achievement in itself was enough to make any man famous. But then he is also the inventor of Stabilite, a powder which we have every reason to regard as important because it can be made quickly in an emergency. A torpedo invention of his, intetided to do -away with compressed air, has also been bought by the Government. Mr. Maxim is a member of the Naval Con- sul I i)ig Board.

��to immerse the cotton in the acid, and when it was thoroughly nitrated to place it in a centrifugal machine and wring out the acid and throw it into an excess of water to wash out the remainder.

The way that is employed principal- ly by the United States Navy is to do the nitrating in a centrifugal ma- chine and when the nitrating is complete to set the centrifugal ma- chine in motion, which extracts the acid from the ni- trocellulose. There- upon the nitrocellu- lose is qui(:kly and thoroughly washed. After the wash- ing process is com- pleted there is a quantity of acid remaining, and also there are con- tained in the nitro- cellulose certain unstable co m- poimds. These are removed by thor- oughly boiling the nitrocellulose in a large excess of water.

After this is done the nitrocellulose is pulped in an ordi- nary pulping ma- chine, like that used in making pa- per pulp. When this is thoroughly done the finely pulped nitrocellu- 1 o s e is gathered and pressed into cylinders. It still contains a consid- erable percentage of water, which must be removed in or- der to dissolve or gelatinate it as a step in converting it into smokeless powder.

This is done by forcing alcohol under pressure through the mass of pulped

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