610 TRANSACTIONS OF SECTION G. 
deliberately abstained from busying himself with marketable inventions arising 
out of his discoveries, excusing himself on the ground that he had no time to 
spare for money-making. It is equally true, and equally to the point, that Faraday, 
when he had established a new fact or a new physical relation, ceased from busying 
himself with it and pronounced that it was now ready to be handed over to the 
mathematicians. But, admitting all these commonplaces as to the value of 
abstract science in itself and for its own sake, admitting also the proposition 
that sooner or later the practical applications are bound to follow on upon the 
discovery, it yet remains true that in this thing the temperament of the 
discoverer counts for something. There are scientific investigators who cannot 
pursue their work if troubled by the question of ulterior applications; there are 
others no less truly scientific who simply cannot work without the definiteness 
of aim that is given by a practical problem awaiting solution. There are 
Willanses as well as Regnaults; there are Whitworths as well as Poissons. 
The world needs both types of investigator; and it needs, too, yet another type 
of pioneer—namely, the man who, making no claim to original discovery, by 
patient application and intelligent skill turns to industrial fruitfulness the results 
already attained in abstract discovery. 
There is, however, another aspect of the relation between pure and applied 
science, the significance of which has not been hitherto so much emphasised, but 
yet is none the less real—the reaction upon science and upon scientific discovery 
of the industrial applications. For while pure science breeds useful inventions, 
it is none the less true that the industrial development of useful inventions fosters 
the progress of pure science. No one who is conversant with the history, for 
example, of optics can doubt that the invention of the telescope and the desire to 
perfect it were the principal factors in the outburst of optical science which we 
associate with the names of Newton, Huygens, and Euler. The practical applica- 
tion, which we know was in the minds of each of these men, must surely have 
been the impelling motive that caused them to concentrate on abstract optics 
their great and exceptional powers of thought. It was in the quest—the hope- 
less quest—of the philosopher’s stone and the elixir of life that the foundations 
of the science of chemistry were laid. The invention of the art of photography 
has given immense assistance to sciences as widely apart as meteorology, ethno- 
logy, astronomy, zoology, and spectroscopy. Of the laws of heat men were 
profoundly ignorant until the invention of the steam engine compelled scientific 
investigation; and the new science of thermodynamics was born. Had there 
been no industrial development of the steam engine, is it at all likely that the world 
would ever have been enriched with the scientific researches of Rankine, Joule, 
Regnault, Hirn, or James Thomson ? The magnet had been known for centuries, 
yet the study of it was utterly neglected until the application of it in the mariners’ 
compass gave the incentive for research. 
The history of electric telegraphy furnishes a very striking example of this 
reflex influence of industrial applications. The discovery of the electric current 
by Volta and the investigation of its properties appear to have been stimulated 
by the medical properties attributed in the preceding fifty years to electric 
discharges. But, once the current had been discovered, a new incentive 
arose in the dim possibility it suggested of transmitting signals to a distance. 
This was certainly a possibility, even when only the chemical effects of the 
current had yet been found out. Not, however, until the magnetic effects 
of the current had been discovered and investigated did telegraphy assume 
commercial shape at the hands of Cooke and Wheatstone in England and 
of Morse and Vail in America, Let us admit freely that these men were 
inventors rather than discoverers: exploiters of research rather than pioneers. 
They built upon the foundations laid by Volta, Oersted, Sturgeon, Henry, and a 
host of less famous workers. But no sooner had the telegraph become of industrial 
importance, with telegraph lines erected on land and submarine cables laid in the 
sea, than fresh investigations were found necessary ; new and delicate instruments 
must be devised; means of accurate measurement heretofore undreamed of must 
be found; standards for the comparison of electrical quantities must be created, 
