The influence of this invention has escaped the notice of many of us, for the reason that it has spread so gradually, and has been of such a character as to fail to strike the imagination from its lack of spectacularity. But the idea of what we now call "quantity production" has spread to all the fields of the manufacturing world, and is the basis of much of the enormous industrial progress of the last half century. It is rendered possible mainly by making the machinery automatic, or nearly so. Without such exaggeration, America may justly claim the contribution of automaticity to the Machine of Civilization. In 1851, Dr. Charles G. Page produced the first electric locomotive. Like many pioneers, it did not achieve practical success itself, but it supplied a stepping stone to further progress. In the same year, Seymour produced his self-rakers for harvesters, and Gorrie invented the ice-making machine. Two more important inventions were the ophthalmoscope, invented by Helmholtz, and the "Ruhmkorff coil," invented by the man whose name still clings to it. The ophthalmoscope reminds one of the stethoscope; so simple it is, so perfect and so useful. It consists merely of a small concave mirror with a hole in it, a lamp and a small convex lens: the mirror being held so that one eye of a physician can look through it, and the lens being placed conveniently by the physician near the eye of a patient. The mirror reflects light from the lamp towards the patient's eye, and the convex lens concentrates them on whatever is to be examined--usually the interior of an eye. This instrument belongs in the small class of inventions already spoken of, in which the original conception was so perfect, that the acts of developing it into a concrete instrument and then producing the instrument were easily performed. The Ruhmkorff coil is in the same class; for it consists merely of two coils of wire; one "primary" coil being of coarse wire and connected with a source of electric current, and the other "secondary" coil of fine wire placed around the coil of coarse wire. If the current in the primary coil be made or broken or changed in force or direction, currents are "induced" in the secondary coil; the strength of the two currents varying relatively according to the sizes and lengths of the wires in the two coils. This invention has an interest apart from its usefulness, in the fact that Ruhmkorff invented it for purposes of scientific study, and that no utilization of it for everyday life occurred until nearly half a century later. Then Ruhmkorff coils were made into "transformers" for use in "stepping down" the small high voltage currents needed for transmitting electric currents over long distances, into the larger but lower voltage currents needed for actuating electric lights and motors.