To a good many of us the inventor is the true hero for he multiplies the
working value of life. He performs an old task with new economy, as when
he devises a mowing-machine to oust the scythe; or he creates a service
wholly new, as when he bids a landscape depict itself on a photographic
plate. He, and his twin brother, the discoverer, have eyes to read a
lesson that Nature has held for ages under the undiscerning gaze of
other men. Where an ordinary observer sees, or thinks he sees,
diversity, a Franklin detects identity, as in the famous experiment here
recounted which proves lightning to be one and the same with a charge of
the Leyden jar. Of a later day than Franklin, advantaged therefor by new
knowledge and better opportunities for experiment, stood Faraday, the
founder of modern electric art. His work gave the world the dynamo and
motor, the transmission of giant powers, almost without toll, for two
hundred miles at a bound. It is, however, in the carriage of but
trifling quantities of motion, just enough for signals, that electricity
thus far has done its most telling work. Among the men who have created
the electric telegraph Joseph Henry has a commanding place. A short
account of what he did, told in his own words, is here presented. Then
follows a narrative of the difficult task of laying the first Atlantic
cables, a task long scouted as impossible: it is a story which proves
how much science may be indebted to unfaltering courage, to faith in
ultimate triumph.
To give speech the wings of electricity, to enable friends in Denver and
New York to converse with one another, is a marvel which only
familiarity places beyond the pale of miracle. Shortly after he
perfected the telephone Professor Bell described the steps which led to
its construction. That recital is here reprinted.
A recent wonder of electric art is its penetration by a photographic ray
of substances until now called opaque. Professor Röntgen's account of
how he wrought this feat forms one of the most stirring chapters in the
history of science. Next follows an account of the telegraph as it
dispenses with metallic conductors altogether, and trusts itself to that
weightless ether which brings to the eye the luminous wave. To this
succeeds a chapter which considers what electricity stands for as one of
the supreme resources of human wit, a resource transcending even flame
itself, bringing articulate speech and writing to new planes of facility
and usefulness. It is shown that the rapidity with which during a single
century electricity has been subdued for human service, illustrates that
progress has leaps as well as deliberate steps, so that at last a gulf,
all but infinite, divides man from his next of kin.
At this point we pause to recall our debt to the physical philosophy
which underlies the calculations of the modern engineer. In such an
experiment as that of Count Rumford we observe how the corner-stone was
laid of the knowledge that heat is motion, and that motion under
whatever guise, as light, electricity, or what not, is equally beyond
creation or annihilation, however elusively it may glide from phase to
phase and vanish from view. In the mastery of Flame for the superseding
of muscle, of breeze and waterfall, the chief credit rests with James
Watt, the inventor of the steam engine. Beside him stands George
Stephenson, who devised the locomotive which by abridging space has
lengthened life and added to its highest pleasures. Our volume closes by
narrating the competition which decided that Stephenson's "Rocket" was
much superior to its rivals, and thus opened a new chapter in the
history of mankind.
GEORGE ILES.
