United States. In both patents he describes how he proposed to make a tire for all kinds of vehicles consisting of a hollow rubber tube, with an inner mixed canvas and rubber lining, a tube and a screw cup by which to inflate it, and several ways for preventing punctures. To obviate the bad results of punctures he proposed also to make his tire in sectional compartments, so that if one compartment was punctured the others would still hold good. He also proposed to use vulcanised rubber, thus utilising the then very recent discovery of Goodyear of mixing sulphur with soft rubber, and to apply the same to the canvas lining.

And, now, when the last decade of the century had been reached, and after a century's hard work by the inventors, the present wonderful vehicle, known as the "safety bicycle," had obtained a successful and permanent foothold among the vehicles of mankind. Proper proportions, low wheels, chain-gearing, treadles, pedals and cranks, cushion and pneumatic tires, drop frames, steel spokes like a spider's web, ball-bearings for the crank and axle parts, a springsupported cushioned seat which could be raised or lowered, adjustable handles, and the clearest-brained scientific mechanics to construct all parts from the best materials and with mathematical exactness-all this has been done. To these accomplishments have been added a great variety of tires to prevent wear and puncturing, among which are self-healing tires, having a lining of viscous or plastic rubber to close up automatically the air holes. Many ways of clamping the tire to the rim have been contrived. So have brakes of various descriptions, some consisting of disks on the driving shaft, brought into frictional contact by a touch of the toe on the pedal, as a substitute for

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those applied to the surface of the tire, known as spoon brakes"; saddles, speed-gearings, men's machines in which by the removal of the upper bar the machine is converted into one for the use of women; the substitution of the direct action, consisting of beveled gearing for the sprocket chain, etc., etc.

The ideas of William Thomson as to pneumatic and cushioned tires are now, after a lapse of fifty years, generally adopted. Even sportsmen were glad to seize upon them, and wheels of sulkies, provided with the pneumatic tires, have enabled them to lower the record of trotting horses. Their use on many other vehicles has accomplished his objects, "of lessening the power required to draw carriages, rendering the motion easier, and diminishing the noise."

It is impossible to overlook the fact in connection with this subject that the processes and machinery especially invented to make the various parts of a bicycle are as wonderful as the wheel itself. Counting the spokes there are, it is estimated, more than 300 different parts in such a wheel. The best and latest inventions and discoveries in the making of metals, wood, rubber and leather have been drawn upon in supplying these useful carriers. And what a revolution they have produced in the making of good roads, the saving of time, the dispatch of business, and more than all else, in the increase of the pleasure, the health and the amusement of mankind!

It was quite natural that when the rubber cushion and pneumatic tires rounded the pleasure of easy and noiseless riding in vehicles that Motor vehicles should be revived and improved. So we have the Automobiles in great variety. Invention has been and is still being greatly exercised as to the best mo

tive power, in the adaption of electric motors, oil and gasoline or vapour engines, springs and air pumps, in attempts to reduce the number of complicated parts, and to render less strenuous the mental and muscular strain of the operator.

Traction Engines.-The old road engines that antedated the locomotives are being revived, and new ideas springing from other arts are being incorporated in these useful machines to render them more available than in former generations. Many of the principles and features of motor vehicles, but on a heavier scale, are being introduced to adapt them to the drawing of far heavier loads. Late devices comprise a spring link between the power and the traction wheel to prevent too sudden a start, and permit a yielding motion; steering devices by which the power of the engine is used to steer the machine; and application of convenient and easily-worked brakes.

An example of a modern traction engine may be found attached to one or more heavy cars adapted for street work, and on which may be found apparatus for making the mixed materials of which the roadbed is to be constructed, and all of which is moved along as the road or street surface is completed. When these fine roads become the possession of a country light traction engines for passenger traffic will be found largely supplanting the horse and the steam railroad engines.

Brakes, railway and electric, have already been referred to in the proper chapters. In the latest system of railroading greater attention has been paid to the lives and limbs of those employed as workmen on the trains, especially to those of brakemen. And if corporations have been slow to adopt such merciful devices, legislatures have stepped in to

help the matter. One great source of accidents in this respect has been due to the necessity of the brakemen entering between the cars while they are in motion to couple them by hand. This is now being abolished by automatic couplers, by which, when the locking means have been withdrawn from connection or thrown up, they will be so held until the cars meet again, when the locking parts on the respective cars will be automatically thrown and locked, as easily and on the same principle as the hand of one man may clasp the hand of another.

The comfort of passengers and the safety of freight have also been greatly increased by the invention of Buffers on railroad cars and trains to prevent sudden and violent concussion. Fluid pressure car buffers, in which a constant supply of fluid under pressure is provided by a pump or train pipe connected to the engine is one of a great variety.

Another notable improvement in this line is the splendid vestibule trains, in which the cars are connected to one another by enclosed passages and which at their meeting ends are provided with yieldingly supported door-like frames engaging one another by frictional contact, usually, whereby the shock and rocking of cars are prevented in starting and stopping, and their oscillation reduced to a minimum.

As collisions and accidents cannot always be prevented, car frames are now built in which the frames are trussed, and made of rolled steel plates, angles, and channels, whereby a car body of great resistance to telescoping or crushing is obtained.

CHAPTER XXIX.

SHIPS AND SHIP-BUILDING.

"Far as the breeze can bear, the billows foam,
Survey our empire, and behold our home."

"Ships are but boards," soliloquised the crafty Shylock, and were this still true, yet this present period has seen wonderful changes in construction.

The high castellated bows and sterns and long prows of The Great Harry, of the seventeenth century, and its successors in the eighteenth, with some moderation of cumbersome matter, gave way to lighter, speedier forms, first appearing in the quickgliding Yankee clippers, during the first decade of the nineteenth century.

Eminent naval architects have regarded the proportions of Noah's ark, 300 cubits long, 50 cubits broad and 30 cubits high, in which the length was six times the breadth, and the depth three-fifths of the breadth, as the best combination of the elements of strength, capacity and stability.

Even that most modern mercantile vessel known as the "whale-back" with its nearly flat bottom, vertical sides, arched top or deck, skegged or spoonshaped at bow and stern, straight deck lines, the upper deck cabins and steering gear raised on hollow turrets, with machinery and cargo in the main hull, has not departed much from the safe rule of proportions of its ancient prototype.

But in other respects the ideas of Noah and of the