Part 43 (1/2)

Where did the Ferris Wheel get Its Name?

The Ferris wheel was named after its builder, George W. Ferris, an able engineer, now dead.

The original Ferris wheel was exhibited at the Chicago World's Fair. It was a remarkable engineering feature.

Its diameter was 270 feet and its circ.u.mference 825 feet. Its highest point was 280 feet. The axle was a steel bar, 45 feet long and 32 inches thick. Fastened to each of the twin wheels was a steel hub 16 feet in diameter. The two towers at the axis supporting the wheel were 140 feet high, and the motive power was secured from a 1,000 horse-power steam engine under the wheel.

The thirty-six cars on the wheel each comfortably seated forty persons.

The wheel and pa.s.sengers weighed 12,000 tons.

By the Ferris wheel the almost indefinite application of the tension spoke to wheels of large dimensions has been vindicated, the expense being far smaller than that of the stiff spoke.

[Ill.u.s.tration: STEEL RAIL MILL

Interior view of the Bethlehem Steel Company's rail mill finis.h.i.+ng department, showing the machinery for straightening and drilling rails.]

What is Done to Keep Railroad Rails from Breaking?

The breaking of rails has been the cause of much attention on the part of railroad and steel engineering experts ever since the tendency toward the construction of heavy locomotives and greater train loads became evident.

The report of the Interstate Commerce Commission for 1915 gave broken rails as the cause of 3,345 accidents, in which 205 people were killed and 7,341 were injured, with a property loss of $3,967,188. A steel man is authority for the statement that one cold winter day in 1913, a single locomotive, making excessive speed, broke about a hundred rails in the distance of a mile on one of the leading railroad systems.

Both steel and railroad men were, therefore, much interested in the announcement made by the New York Central Railroad, in August, 1916, to the effect that the road's staff of specialists had discovered the cause and remedy for the hidden flaws in steel rails. It was said that no rails produced under the specifications provided by them had yet developed any fissures.

The process by which those rails were prevented from developing fissures consisted mainly of rolling them from reheated blooms, and although that method is said to have been used in a number of rail mills for many years, no mention had previously been recorded of the prevention of breakage in that way. The experiments are, therefore, sure to be watched with a great deal of interest, and it is probable that fewer accidents will occur from broken rails in the near future.

The technical man will be interested in an outline printed in the _Iron Age_, which said: ”Induced interior transverse fissures in basic open-hearth rails are due in part to an occasional hot rail being cooled so rapidly by the rolls or so chilled by the gusts of air before recalescence on the hot beds as to cause a log of some of the transformations of the metal in the interior of the rail head. Induced interior transverse fissures can only develop in the track from the effects of preceding causes, either of which is no longer a mystery.”

The report of the railroad experts also laid stress on the theory that ”gagging” rails--subjecting them to blows for the purpose of straightening them--was also likely to cause faults by injuring the metal.

How does a ”Master Clock” Control Others by Electricity?

With the aid of electric currents, one clock can be made to control other clocks, so as to make them keep accurate time.

By means of this method one high-cla.s.s clock, usually in an astronomical observatory, compels a number of other clocks at considerable distances to keep time with it.

The clocks thus controlled ought to be so regulated that if left to themselves they would always gain a little, but not more than a few minutes per day.

The pendulum of the controlling clock, in swinging to either side, makes a brief contact, which completes the circuit of a galvanic battery, and thus sends a current to the controlled clock. The currents pa.s.s through a coil in the bob of the pendulum of the controlled clock, and the action between these currents and a pair of fixed magnets urges the pendulum to one side and to the other alternately. The effect is that, though the controlled clock may permanently continue to be a fraction of a second in advance of the controlling clock, it can never be so much as half a second in advance.

An electrically controlled clock usually contains a small magnetic needle, which shows from which direction the currents are coming. The arrangements are usually such that at every sixtieth second no current is sent, and the needle stands still. Any small error is thus at once detected.

The Story of the Calculating Machine

How did Men Learn to Count?