Inventions in the Century

by William Henry Doolittle

Brewster also demonstrated the utility of dioptric lenses, and zones in lighthouse illumination; and in which field Faraday and Tyndall also subsequently worked with the addition of electrical appliances. The labours of these three men have illuminated the wildest waters of the sea and preserved a thousand fleets of commerce and of war from awful shipwreck.

As illustrating the difficulties sometimes encountered in introducing an invention into use, the American Journal of Chemistry some years ago related that the Abbé Moigno, in introducing the stereoscope to the savants of France, first took it to Arago, but Arago had a defect of vision which made him see double, and he could only see in it a medley of four pictures; then the Abbé went to Savart, but unfortunately Savart had but one eye and was quite incapable of appreciating the thing. Then Becquerel was next visited, but he was nearly blind and could see nothing in the new optical toy. Not discouraged, the Abbé then called upon Puillet of the Conservatoire des Arts et Metiers. Puillet was much interested, but he was troubled with a squint which presented to his anxious gaze but a blurred mixture of images. Lastly Brot was tried. Brot believed in the corpuscular theory of light, and was opposed to the undulatory theory, and the good Abbé not being able to assure him that the instrument did not contradict his theory, Brot refused to have anything to do with it. In spite, however, of the physical disabilities of scientists, the stereoscope finally made its way in France.

Besides increasing the power of the eye to discover the secrets and beauties of nature, modern invention has turned upon the eye itself and displayed the wonders existing there, behind its dark glass doors. It was Helmholtz who in 1851 described his Ophthalmoscope. He arranged a candle so that its rays of light, falling on an inclined reflector, were thrown through the pupil of the patient’s eye, whose retina reflected the image received on the retina back to the mirror where it could be viewed by the observer. This image was the background of the eye, and its delicate blood vessels and tissues could thus be observed. This instrument was improved and it gave rise to the contrivance of many delicate surgical instruments for operating on the eye.

The Spectroscope is an instrument by which the colours of the solar rays are separated and viewed, as well as those of other incandescent bodies. By it, not only the elements of the heavenly bodies have been determined, but remarkable results have been had in analysing well-known metals and discovering new ones. Its powers and its principles have been so developed during the century by the discoveries, inventions and investigations of Herschel, Wollaston, Fraunhofer, Bronsen and Kirchoff, Steinheil, Tyndall, Huggins, Draper and others, that spectrum analysis has grown from the separation of light into its colours by the prism of Newton, to what Dr. Huggins has aptly termed “a new sense.”

We have further referred to this wonderful discovery in the Chapter on Chemistry.

The inventions and improvements in optical instruments gave rise to great advances in the making of lenses, based on scientific principles, and not resting alone on hard work and experience. Alvan Clark a son of America, and Prof. Ernst Abbe of Germany, have within the last third of the century produced a revolution in the manufacture of lenses, and thereby extended the realms of knowledge to new worlds of matter in the heavens and on earth.

Solarmeter.—In 1895 a United States patent was granted to Mr. Bechler for an instrument called a solarmeter. It is designed for taking observations of heavenly bodies and recording mechanically the parts of the astronomical triangle used in navigation and like work. Its chief purpose is to determine the position of the compass error of a ship at sea independently of the visibility of the sea horizon. If the horizon is clouded, and the sun or a known star is visible, a ship’s position can still be determined by the solarmeter.

Instruments for Measuring the Position and Distances of Unseen Objects.—Some of the latest of such instruments will enable one to see and shoot at an object around a corner, or at least out of sight. Thus a United States patent was granted to Fiske in 1889, wherein it is set forth that by stationing observers at points distant from a gun, which points are at the extremities of a known base line, and which command a view of the area within the range of the gun, the observers discover the position and range of the object by triangulation and set certain pointers. By means of electrical connection between those pointers and pointers at the gun station based on the system of the Wheatstone bridge, the latter pointers, or the guns themselves serving as pointers, may be placed in position to indicate the line of fire. By a nice arrangement of mirror and lenses attached to a firearm the same object may be accomplished. Similar apparatuses in which the reflectory surfaces of mirrors mounted on an elevated frame-work, and known as Polemoscopes and Altiscopes and Range-Finders, have also been invented, and used with artillery. But such devices may be profitably used for more peaceful and amusing purposes.

Born with the ear attuned to music and the eye to observe beauty, the hand of Art was to trace and make permanent the fleeting forms which melody and the eye impressed upon the soul of man.

In fact modern science has demonstrated that tones and colours are inseparable. Bell and Tainter with their photophone have converted the undulatory waves of light into the sweetest music. Reversing the process, beautiful flashes of light have been produced from musical vibrations by the phonophote of M. Coulon and the phonoscope of Henry Edmunds.