Heroes of Science: Physicists

by William Garnett

"I need not point out ... the difference in the perceptive powers of the eye and the ear, and the facility and clearness with which the first of these organs conveys ideas to the mind—ideas which, being thus gained, are held far more retentively and firmly in the memory than when introduced by the ear.... Apparatus, therefore, is an essential part of every lecture in which it can be introduced.... When ... apparatus is to be exhibited, some kind of order should be observed in the arrangement of them on the lecture-table. Every particular part illustrative of the lecture should be in view, no one thing should hide another from the audience, nor should anything stand in the way of or obstruct the lecturer. They should be so placed, too, as to produce a kind of uniformity in appearance. No one part should appear naked and another crowded, unless some particular reason exists and makes it necessary to be so."

On October 13, 1813, Faraday left the Royal Institution, in order to accompany Sir Humphry Davy in a tour on the Continent. His journal gives some interesting details, showing the inconveniences of foreign travel at that time. Sir Humphry Davy took his carriage with him in pieces, and these had to be put together after escaping the dangers of the French custom-house on the quay at Morlaix, two years before the battle of Waterloo.

One apparently trivial incident somewhat marred Faraday's pleasure throughout this journey. It was originally intended that the party should comprise Sir Humphry and Lady Davy, Faraday, and Sir Humphry's valet, but at the last moment that most important functionary declined to leave his native shores. Davy then requested Faraday to undertake such of the duties of valet as were essential to the well-being of the party, promising to secure the services of a suitable person in Paris. But no eligible candidate appeared for the appointment, and thus Faraday had throughout to take charge of domestic affairs as well as to assist in experiments. Had there been only Sir Humphry and himself, this would have been no hardship. Sir Humphry had been accustomed to humble life in his early days; but the case was different with his lady, and, apparently, Faraday was more than once on the point of leaving his patron and returning home alone. A circumstance which occurred at Geneva illustrates the position of affairs. Professor E. de la Rive invited Sir Humphry and Lady Davy and Faraday to dinner. Sir Humphry could not go into society with one who, in some respects, acted as his valet. When this point was represented to the professor, he replied that he was sorry, as it would necessitate his giving another dinner-party. Faraday subsequently kept up a correspondence with De la Rive, and continued it with his son. In writing to the latter he says, in speaking of Professor E. de la Rive, that he was "the first who personally at Geneva, and afterwards by correspondence, encouraged and by that sustained me."

At Paris Faraday met many of the most distinguished men of science of the time. One morning Ampère, Clément, and Desormes called on Davy, to show him some iodine, a substance which had been discovered only about two years before, and Davy, while in Paris, and afterwards at Montpellier, executed a series of experiments upon it. After three months' stay, the party left Paris for Italy, viâ Montpellier, Aix, and Nice, whence they crossed the Col de Tende to Turin. The transfer of the carriage and baggage across the Alps was effected by a party of sixty-five men, with sledges and a number of mules. The description of the journey, as recorded in Faraday's diary, makes us respect the courage of an Englishman who, in the early part of this century, would attempt the conveyance of a carriage across the Alps in the winter.

"From Turin we proceeded to Genoa, which place we left afterwards in an open boat, and proceeded by sea towards Lerici. This place we reached after a very disagreeable passage, and not without apprehensions of being overset by the way. As there was nothing there very enticing, we continued our route to Florence; and, after a stay of three weeks or a month, left that fine city, and in four days arrived here at Rome." The foregoing is from Faraday's letter to his mother. At Florence a good deal of time was spent in the Academia del Cimento. Here Faraday saw the telescope with which Galileo discovered Jupiter's satellites, with its tube of wood and paper about three feet and a half long, and simple object-glass and eye-glass. A red velvet electric machine with a rubber of gold paper, Leyden jars pierced by the discharge between their armatures, the first lens constructed by Galileo, and a number of other objects, were full of interest to the recently enfranchised bookbinder's apprentice; but it was the great burning-glass of the grand-duke which was the most serviceable of all the treasures of the museum. With this glass—which consisted of two convex lenses about three feet six inches apart, the first lens having a diameter of about fourteen or fifteen inches, and the second a diameter of three inches—Davy succeeded in burning several diamonds in oxygen gas, and in proving that the diamond consists of little else than carbon. In 1818 Faraday published a paper on this subject in the Quarterly Journal of Science. At Genoa some experiments were made with the torpedo, but the specimens caught were very small and weak, and their shocks so feeble that no definite results were obtained. At Rome Davy attempted to repeat an experiment of Signor Morrichini, whereby a steel needle was magnetized by causing the concentrated violet and blue rays from the sun to traverse the needle from the middle to the north end several times. The experiment did not succeed in the hands of Davy and Faraday, and it was left to the latter to discover a relation between magnetism and light. From Rome they visited Naples and ascended Vesuvius, and shortly afterwards left Italy for Geneva. In the autumn of 1814 they returned from Switzerland through Germany, visiting Berne, Zurich, the Tyrol, Padua, Venice, and Bologne, to Florence, where Davy again carried out some chemical investigations in the laboratory of the academy. Thence they returned to Rome, and in the spring went on to Naples, and again visited Vesuvius, returning to England in April, viâ Rome, the Tyrol, Stuttgart, Brussels, and Ostend.

A fortnight after his return from the Continent Faraday was again assistant at the Royal Institution, but with a salary of thirty shillings a week. His character will be sufficiently evident from the quotations which have been given from his diary and letters. Henceforth we must be mainly occupied with the consideration of his scientific work.

In January, 1816, he gave his first lecture to the City Philosophical Society. In a lecture delivered shortly afterwards before the same society, the following passage, which gives an idea of one of the current beliefs of the time, occurs:—

"The conclusion that is now generally received appears to be that light consists of minute atoms of matter of an octahedral form, possessing polarity, and varying in size or in velocity....

"If now we conceive a change as far beyond vaporization as that is above fluidity, and then take into account also the proportional increased extent of alteration as the changes rise, we shall, perhaps, if we can form any conception at all, not fall far short of radiant matter;[6] and as in the last conversion many qualities were lost, so here also many more would disappear.