Man's physical universe

xanabras

506 MAGNETISM AND ELECTRICITY

and today the capacity of a telegraph system has been increased still

more by sending a number of messages over a single pair of wires at

the same time. In actual practice eight messages are usually sent

simultaneously, but more may be added if desired. Automatic typewriters,

operated directly by the telegraph signals and based on the

use of a group of electromagnets, form the basis of the modern teletype

used in newspaper and police work. One linotype machine could

operate all the other linotype machines in the United States by means

of the telegraph.

Lord Kelvin Perfected the Transatlantic Cable.

When Lord Kelvin (1824-1907), then named William Thomson,

finished his work at Cambridge, one of his examiners remarked to

another, "You and I are just about fit to mend his pens." Lord

Kelvin was one of those rare men, like James Watt, in whom there was

a combination of mechanical ingenuity and scientific genius. There

is no question as to the value of practical application as an incentive

to scientific work. Some of the world's greatest scientists, like Louis

Pasteur, have been spurred on to greater endeavors by the supreme

desire to help solve some of the pressing problems of humanity. Lord

Kelvin expressed this idea as follows:

The life and soul of science is its practical application; and just as the great

advances in mathematics have been made through the desire of discovering

the solution of problems which were of a highly practical kind in mathematical

science, so in physical science many of the greatest advances have been made

in the earnest desire to turn the knowledge of the properties of matter to some

purpose useful to mankind.

Not only did Kelvin make contributions to the science of thermodynamics

and other theoretical studies, but also did he earn the profound

gratitude of all navigators and those whose lives depended on

the latter for his improvements of the compass and his introduction

of the sounding line.

The first transatlantic submarine cable, laid in 1858, soon failed.

Lord Kelvin designed a new type of strand cable better adapted to

stand the strain of laying and repairing and invented the mirror

galvanometer and siphon recorder for receiving the messages sent

over the cables. Both instruments were applications of electromagnets,

as are the majority of electrical measuring instruments. Lord Kelvin

also designed electrical measuring instruments for almost every purpose.

In 1896 a tremendous celebration was held in honor of this great

physicist, fertile inventor, and inspiring and beloved teacher. As part

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