# Passages from the Life of a Philosopher/Chapter XXXII

CHAPTER XXXII.
various reminiscences.
On Preventing the Forgery of Bank-Notes.
In 1836 imitations of bank-notes were so easily made, and the forgeries so numerous, that the Directors of the Bank of England resolved on appointing a small committee to examine the subject, and advise them upon a remedy.
The Governor of the Bank wrote to ask me whether I would consent to act upon that committee. Not being myself a professional engineer, I entertained some doubts whether my presence would be agreeable to the profession. Having consulted Sir Isambard Brunel and the late Mr. Bryan Donkin, who had been also applied to, they both pressed me to join them in the inquiry.
We examined the existing means of preventing forgery, which were certainly very defective. The system of the Bank of Ireland which had recently been greatly improved, was then discussed. Not many months before, I had carefully examined the whole plan at Dublin. After a full deliberation on the subject, I drew up our Report, which unanimously recommended its adoption. The identity of the steel plates from which the bank-notes were to be printed was secured by Perkins's plan of multiplying the number of such plates by impressing them all from one roll of hardened steel.
This plan answered its purpose fully at that time. It has, ​however, been superseded within the last few years. I had, through the kindness of the late Governor of the Bank of England, an opportunity of examining their most recent improvement. The discovery of the process of making facsimiles of a wood engraving, by means of the electro-chemical deposit of copper, has now enabled the Bank to return to the more rapid process of surface printing.
It is probable, from the great progress of the mechanical arts, that these periods for revising methods of preventing forgery will occur at more frequent intervals.
I derived great pleasure from being permitted, as an amateur, to join in this interesting inquiry with my professional friends, whose knowledge and character I highly valued.
Subsequently I received the unexpected gratification of a vote of thanks from the Governor and Company of the Bank of England—an honour usually reserved for warriors and statesmen.
An Émeute.
On one of my visits to Paris I had the pleasure of dining at the Bank of France. During dinner, in the midst of an interesting conversation, the Chairman received a note: having glanced over it he put it down by his side on the table.
On the occurrence of a pause in the conversation, thinking the note might possibly require an immediate reply, I inquired whether such was the case. "No," said my host, "it is of no consequence. It is only an émeute;" which he then informed me was occurring in a distant part of Paris.
Letters of Credit.
Letters of credit are specially addressed to certain bankers at various places with whom your own banker is in correspondence.
​It has on several occasions happened to me to want cash either for myself or to accommodate some friend at places where my own letters were not addressed to any firm. At Frankfort I made a purchase of books. I had a certain amount of the usual circular letters, but as these were payable in a great many cities, and as I proposed visiting Egypt, I did not wish to part with them. I therefore went to the house of Rothschild, hoping to get an advance on my letter of credit, although it was not addressed to that firm. But it being Saturday, no business was done. I therefore inquired for another banker of reputation, and was directed to M. Koch.
I accordingly called at his counting-house, stated my reason for wanting the money, showed him my circular notes and letters of credit, and asked whether, under these circumstances, he would cash my check for twenty pounds. He immediately remarked that he had frequently visited England, and that most probably we had several common friends, as it soon appeared, for the first person he mentioned was Professor Sedgwick.
M. Koch not only advanced me the money, but he was so kind as to invite me to dinner on the following day, and to give me a seat in his box at the opera on the first appearance of Madamoiselle Sontag on the Frankfort stage.
I remember at least three other occasions in which I got money for some of my English friends at towns where my letter of credit was not addressed to any banker. In those cases I only asked them to take my cheque, send it to London, and when they had received the amount, to pay it over to me. I also mentioned that I was known to several persons resident in Geneva and in Berlin where these occurrences happened. In each case the banker immediately let me have the money my friends wanted.
​The only instance in which I was refused amused me very much. I spent a few weeks at Modena, where I had purchased a microscope and several other philosophical instruments. One morning I went to the wealthy firm of Sanguinetti, and mentioning my object to one of the partners, at the same time showing him my letter of credit, asked if, under these circumstances, he would give me cash for a draft of twenty pounds on my banker in London. He replied very courteously that it was the rule of their house to give credit only upon letters addressed to them by their own correspondent in London. I remarked that it was quite necessary in matters of business to adhere to fixed rules, and that when made aware of their practice I should be the last person to ask them to deviate from it.
Early the next morning a carriage drove up to the door of my lodgings and an elderly gentleman was announced. This was M. Sanguinetti, the senior partner of the firm. He told me he came to apologize for the refusal of his junior partner on the preceding day, and to offer to give me cash for my cheque to whatever amount I might require.
I replied that, a near relative of my own having formerly been a banker in London, I was aware of the necessity of a rigid observance of rules of business, and that his young partner had not only done his duty, but, I added, that he had done it in the most courteous manner. M. Sanguinetti was so obliging and so pressing, that I found it difficult to accept the advance of so small a sum: however, it was all arranged, and he left me.
I then sent for my landlord and inquired whether he had had any communication with M. Sanguinetti. He replied that the old gentleman, the head of the firm, had called the preceding evening, and asked him who I was. "And what," ​said I to my landlord, "was your answer?"—"I told Him you were a Milord Anglais," replied my host.—"I am not a Milord Anglais," I observed; "but why did you tell him so?"—"Because," said my landlord, "when the minister paid you a visit, you sat down in his presence."
The explanation of the affair was this. Soon after my arrival at Modena, I called on the Marquis Rangoni, a distinguished mathematician, who had written a profound comment on Laplace's "Théorie des Fonctions Génératrices." I had not brought any letter of introduction, but had merely sent up my card. The Marquis Rangoni received me very cordially, and we were soon in deep discussion respecting some of the most abstract questions of analysis. He returned my visit on the following day, when he resumed the discussion, and I showed him some papers connected with the subject. I was aware of the title of the Marquis Rangoni to respect, as arising from his own profound acquaintance with analysis, but I was now, for the first time, informed that he was a man of great importance in the little Dukedom of Modena, for he was the Prime Minister of the Grand Duke—in fact, the Palmerston of Modena. This at once explained the attention I received from the wealthy banker.
The Speaker.
One Saturday morning an American gentleman who had just arrived from Liverpool, where he had landed from the United States on the previous day, called in Dorset Street. He was very anxious to see the Difference Engine, and quite fitted by his previous studies for understanding it well. I took him into the drawing-room in which the machine then resided and gave him a short explanation of its structure. As I expected a large party of my friends in the evening, ​amongst whom were a few men of science, I asked him to join the party.
It so happened on that day that the Speaker had a small dinner-party. The Silver Lady was accidentally mentioned, and greatly excited the curiosity of the lady of the house. As the whole of this small party, comprising three or four of my most intimate friends, were coming to my house in the evening, they proposed that the Speaker and his wife should accompany them to my party, assuring them truly that I should be much gratified by the visit.
The Silver Lady happened to be in brilliant attire, and after mentioning the romance of my boyish passion, the unexpected success of her acquisition, and the devoted cultivation I bestowed upon her education, I proceeded to set in action her fascinating and most graceful movements.
A gay but by no means unintellectual crowd surrounded the automaton. In the adjacent room the Difference Engine stood nearly deserted: two foreigners alone worshipped at that altar. One of them, but just landed from the United States, was engaged in explaining to a learned professor from Holland what he had himself in the morning gathered from its constructor.
Leaning against the doorway, I was myself contemplating the strongly contrasted scene, pleased that my friends were relaxing from their graver pursuits, and admiring the really graceful movements produced by mechanism; but still more highly gratified at observing the deep and almost painful attention of my Dutch guest, who was questioning his American instructor about the mechanical means I had devised for accomplishing some arithmetical object. The deep thought with which this explanation was attended to, ​suddenly flashed into intense delight when the simple means of its accomplishment were made apparent.
My acute and valued friend, the late Lord Langdale, who had been observing the varying changes of my own countenance, as it glanced from one room to the other, now asked me, "What new mischief are you meditating?"—"Look," said I, "in that further room—England. Look again at this—two Foreigners."
Ancient Music.
Many years ago some friends of mine invited me to accompany them to the concert of ancient music, and join their supper-party after it was over.
My love of music is not great, but for the pleasure of the society I accepted the invitation. On our meeting at the supper-table, I was overwhelmed with congratulations upon my exquisite appreciation of the treat we had just had. I was assured that though my expression of feeling was of the quietest order, yet that I was the earliest to approve all the most beautiful passages.
I accepted modestly my easily-won laurels, and perhaps my taste for music might have survived in the memory of my friends, when my taste for mechanism had been forgotten. I will, however, confide to the public the secret of my success. Soon after I had taken my seat at the concert, I perceived Lady Essex at a short distance from me. Knowing well her exquisitely sensitive taste, I readily perceived by the expression of her countenance, as well as by the slight and almost involuntary movement of the hand, or even of a finger, those passages which gave her most delight. These quiet indications, unobserved by my friends, formed the electric wire by which I directed the expressions of my own ​countenance and the very modest applause I thought it prudent to develop.
After receiving the congratulations of my friends upon my great musical taste, I informed them how easily that reputation had been acquired. Such are the feeble bases on which many a public character rests.
During my residence with my Oxford tutor, whilst I was working by myself on mathematics, I occasionally arrived at conclusions which appeared to me to be new, but which from time to time I afterwards found were already well known. At first I was much discouraged by these disappointments, and drew from such occurrences the inference that it was hopeless for me to attempt to invent anything new. After a time I saw the fallacy of my reasoning, and then inferred that when my knowledge became much more extended I might reasonably hope to make some small additions to my favourite science.
This idea considerably influenced my course during my residence at Cambridge by directing my reading to the original papers of the great discoverers in mathematical science. I then endeavoured to trace the course of their minds in passing from the known to the unknown, and to observe whether various artifices could not be connected together by some general law. The writings of Euler were eminently instructive for this purpose. At the period of my leaving Cambridge I began to see more distinctly the object of my future pursuit.
It appeared to me that the highest exercise of human faculties consisted in the endeavour to discover those laws of thought by which man passes from the known to that which ​was unknown. It might with propriety be called the philosophy of invention. During the early part of my residence in London, I commenced several essays on Induction, Generalization, Analogy, with various illustrations from different sources. The philosophy of signs always occupied my attention, and to whatever subject I applied myself I was ever on the watch to perceive and record the links by which the new was connected with the known.
Most of the early essays I refer to were not sufficiently matured for publication, and several have appeared without any direct reference to the great object of my life. I may, however, point out one of my earlier papers in the "Philosophical Transactions for 1817," which, whilst it made considerable additions to a new branch of science, is itself a very striking instance of the use of analogy for the purpose of invention. I refer to the "Essay on the Analogy between the Calculus of Functions and other Branches of Analysis."—Phil. Trans. 1817.