By permission of Messrs. Chance Bros. and Co., Ltd. A Huge Lamp
The marvellous arrangement of lenses and prisms which enables the lighthouse to send out its guiding flashes, with the mechanism
for turning it. Made for "Chilang" Lighthouse, China Frontispiece
MARVELS OF
SCIENTIFIC INVENTION
AN INTERESTING ACCOUNT IN NON-TECHNICAL LANGUAGE OF THE INVENTION OF GUNS, TORPEDOES, SUBMARINES MINES, UP-TO-DATE SMELTING, FREEZING, COLOUR PHOTOGRAPHY, AND MANY OTHER RECENT
DISCOVERIES OF SCIENCE
BY
THOMAS W. CORBIN
AUTHOR OF
"ENGINEERING OF TO-DAY," "MECHANICAL INVENTIONS OF TO-DAY," "THE ROMANCE OF SUBMARINE ENGINEERING," &c., &c.
WITH 32 ILLUSTRATIONS & DIAGRAMS PHILADELPHIA
J. B. LIPPINCOTT COMPANY
LONDON: SEELEY, SERVICE & CO. LTD.
1917 [Pg 5]
CONTENTS
page
I.
Digging with Dynamite
9
II.
Measuring Electricity
22
III.
The Fuel of the Future
42
IV.
Some Valuable Electrical Processes
55
V.
Machine-made Cold 67
VI.
Scientific Inventions at Sea 78
VII.
The Gyro-Compass 90
VIII.
Torpedoes and Submarine Mines
98
IX.
Gold Recovery 109
X.
Intense Heat 123
XI.
An Artificial Coal Mine 137
XII.
The Most Striking Invention of Rece
nt Times
149
XIII.
How Pictures can be sent by Wire
176
XIV. A Wonderful Example of Science and Skill 191
XV. Scientific Testing and Measuring 198
XVI. Colour Photography212
XVII. How Science aids the Stricken Collier 220
XVIII. How Science helps to keep us well 231
1
XIX. Modern Artillery 236
Appendix 245
Index 247
[7]
LIST OF ILLUSTRATIONS
A Huge Lamp Frontispiece facing page
First Effect of the Dynamite 16
A Fine Crop 24
Apple-tree planted by Spade 48
Machine-made Ice 72
A Cold Store 80
Dassen Island Lighthouse 88
Measuring Heat 128
The Telewriter 184
A Miners' Rescue Team 208
Pneumatic Hammer Drill 216
An Artificial Coal Mine 224
Sectional view of a 60-pounder Gun 232
Rifles of different Nations 240
DIAGRAMS
fig. page
1. Principle of Galvanometer 30
2. String Galvanometer 31
3. Duddell Thermo-Galvanometer 39
[8]
4. Construction of a Voltmeter 64
5. The Working of a Refrigerating Machine 70
6. Hertz's Machine 155
7. Hertz "Detector" 156
8. 9. 10. Wireless Waves 158
11. A Wireless Antenna 164
12. Poulsen's Machine 166
13. 14. How Pictures are sent by Wire 177
15. Message received by Telewriter189
[9]
MARVELS OF SCIENTIFIC INVENTION
CHAPTER I
DIGGING WITH DYNAMITE
Most people are afraid of the word explosion and shudder with apprehension at the mention of dynamite. The latter, particularly, conjures up visions of anarchists, bombs, and all manner of wickedness. Yet the time seems to be coming when every farmer will regard explosives, of the general type known to the public as dynamite, as among his most trusty implements. It is so already in some places. In the United States explosives have been used for years, owing to the exertions of the Du Pont Powder Company, while Messrs Curtiss' and Harvey, and Messrs Nobels, the great explosive manufacturers, are busy introducing them in Great Britain.
It will perhaps be interesting first of all to see what this terror-striking compound is. One essential feature is the harmless gas which constitutes the bulk of our atmosphere, nitrogen. Ordinarily one of the most lazy, inactive, inert of substances, this gas will, under certain circumstances, enter into combination with others, and when it does so it becomes in some cases the very reverse of its usual peaceful, lethargic self. It is as if it entered reluctantly into these compounds and so introduced an element of instability into them. It is like a dissatisfied partner in a business, ready to break up the whole combination on very slight provocation.
2
And it must be remembered that an explosive is simply some chemical compound which can change suddenly into[10] something else of much larger volume. Water, when boiled, increases to about 1600 times its own volume of steam, and if it were possible
to bring about the change suddenly water would be a fairly powerful explosive. Coal burnt in a fire changes, with oxygen from the atmosphere, into carbonic acid gas, and the volume of that latter which is so produced is much more than that of the combined volumes of the oxygen and coal. When the burning takes place in a grate or furnace we see nothing at all like an explosion, for the simple reason that the change takes place gradually. That is necessarily so since the coal and oxygen are only in contact at the surface of the former. If, however, we grind the coal to a very fine powder and mix it well with air, then each fine particle is in contact with oxygen and can burn instantly. Hence coal-dust in air is an explosive. It used to be thought that colliery accidents were due entirely to the explosion of methane, a gas which is given off by the coal, but it has of recent years dawned upon people that it is the coal-dust in the mine which really does the damage. The explosion of methane stirs up the dust, which then explodes. The former is comparatively harmless, but it acts as the trigger or detonator which lets loose the force pent up in the innocent-looking coal-dust. Hence the greatest efforts in modern collieries are bent towards ridding the workings of dust or else damping it or in some other way preventing it from being stirred up into the dangerous state.
So the essential feature of any explosive is oxygen and something