Blakesley. half the period of the note under consideration. Then, the Mr. the number represented by (2 RK TM)‡. T about 2. The number opposite 2 is 1.673, which represents the square of the current at starting to the square of the current on arrival. The root of this number is about 1.3, so that this current has been degraded by 3 parts in 13. This effect is the greater the higher the pitch of the note, so that we should feel no surprise when Mr. Preece, who has had considerable practical acquaintance with telephones, owns that low rumblings are often all that can be heard. M. Van Rysselberghe appears to have had a similar experience. The fact is that the low tones are the survivors, and the vanishing of sibilant sounds arises from their short periods as notes. In these effects, and not in failures of insulation, must we look for the limits of long-distance articulation. Want of insulation is no doubt a bad thing, but is a small obstacle compared with degradation of current due to capacity. The smaller the resistance of the conductor the less baneful is the capacity, and on that account is it a good thing to substitute copper for iron, not so much because the self-induction is thereby diminished. Touching self-induction, it is often considered an evil under all circumstances. This is by no means the case. Suppose we have a circuit closed by a non-leaking condenser, i.e., one which on a bridge would show a resistance of value infinity. A telephone will, however, produce a current in such a circuit. If self-induction is then gradually added to the circuit by inserting iron wires into a Mr. Mr. Mason. Mr. Preece. coil, the current will gradually increase until a certain point is reached, beyond which it will fall off. If at this critical point we take away both condenser and the causes of self-induction (the wires), and close the circuit over the breach made by the condenser, we shall find the full effect maintained. The presence of the self-induction with the condenser has been able to entirely annihilate the effect of the infinite resistance constituted by the dielectric of the condenser. [The critical condition is different for different periods, i.e., pitches.] A great deal more might be said upon this interesting subject, but I am aware your time is valuable, and will abstain at present. Mr. GEO. A. MASON: I should like to correct Professor Silvanus Thompson on one or two. things-First, that electric light carbon is not the carbon used in either Post Office instruments or the Blake instrument; it is carbon specially prepared and made entirely different. Secondly, the interest of the Western Union Telegraph Company and the American Bell Telephone Company is a joint interest, because the Western Union owns 45 per cent. of the Bell Telephone interest, therefore the interests must be identical. The PRESIDENT: As the hour is very late, I must call on Mr. Preece to reply at once. Mr. W. H. PREECE, in reply, said: I am sorry, Sir, that the discussion has been confined to so few speakers. I should like to have had to reply to a great many, and especially if the replies only required to be so simple as those I have now to make. A remark was made by an early speaker expressing regret that I had not called attention to the form and character of the instruments used by the Post Office. They are manufactured by the Consolidated Telephone Construction Company, whose manager, Mr. Mason, has just spoken to the meeting. Specimens are on the table for examination, and I think that the workmanship turned out by the Consolidated Telephone Construction Company of London quite equals anything seen either in America or on the Continent of Europe. Now, Mr. Van Rysselberghe expressed a hope that when trunk wire working has developed on the Continent England will not keep behind. I can promise him most faithfully that it will Mr. Preece.' not; it never has kept behind when it has had its chance, and I hope that we shall some day show, by the working of the telephone system also, that at any rate England does not mean to be behind even the United States of America. If anybody wants to know one reason why England is now behind as regards telephony, I call the attention of everybody present to an account of how telephones are worked in this country in the columns of Punch to-day. It is a true description of the difficulties that nearly everybody encounters when desiring to speak through the telephone system in London. I say, and I repeat the statement deliberately, that the question of speaking to a distance is not a question of powerful transmitters. There is no doubt that a powerful transmitter will speak better than a weak transmitter, but then I say that is not the question. The question of speaking to a distance rests with the wires and the environment of those wires; it does not rest with the transmitter. Mr. Van Rysselberghe has explained how he spoke through 1,100 miles with perfect ease without any special transmitter, any loud-speaking Hunnings, or the Turnbull improvements, or the Husbands improvement, or Professor Silvanus Thompson's improvement; but he spoke through the ordinary Hughes microphone; and his experience has shown that really the question is not one of transmitters, but of conductors, and of removing the disturbances that I have mentioned. It is a very common way of raising a discussion to impute wrong expressions to the man whose words are referred to. Professor Thompson quoted me as saying that the Post Office officials had made all improvements in telephones. I said nothing of the kind; I said "improvements in working in this country." All improvements in working have been introduced by the Post Office officials. We introduced double-wire working; we did not invent, but we introduced, the twisted wire. The twisted wire was invented by Professor Hughes, who has not suggested one improvement of any sort or kind that has not been readily tried, and, if suitable, adopted. There is no single man-I do not care who he is or from what country he comes-who presents an invention which is not tried, Mr. Preece. and if it is an improvement, and proves capable of successful adoption, it is accepted and well paid for. If one wants to know how improvements have been adopted and are working, let him go to Newcastle-on-Tyne. There is no "calling" on the system there. A man goes to the telephones, lifts the tubes, and speaks to the exchange at once; there is no calling anyone-it seems like magic-no "Who's there?" When he has finished the conversation it is known at once by the replacement of his tubes; there is no mild, meek, indistinct female voice breaking in with 66 Have you finished?" The conversation is carried on as between two men together, and the moment it is over the exchange knows it, and a second subscriber is put through without loss of time. There is no overhearing, and no disturbance; everything goes on as perfectly between the six or seven towns I named in the North of England as it would in any local exchange. I want also to correct Professor Silvanus Thompson on another very serious point, and it is one of the most curious errors, I think, that has ever become a public delusion. No decision of any court and no law has ever said that a telephone is a telegraph; it has never done anything of the kind. The Post Office has no more control over the telephone than anyone in this room. We cannot buy telephones, because the United Telephone Company will not sell us any. It was only by a clever piece of business, negotiated before a company was floated (since absorbed by the United Company), that we succeeded in getting the disposal of 20,000 telephones. What the court decided was that messages sent by telegraph, by telephone, by tube, or by any electrical means, between one person and another were telegrams, and came within the rights of the Postmaster-General. Nobody can send messages for money outside the Act of Parliament that controls the telegraphs of this country. The telephone is a telephone, and the Post Office has no control over the telephone whatever. I am glad that Mr. Van Rysselberghe made his promise, and we will keep him to his word. He is about to carry two wires from Paris to Rotterdam and Amsterdam, and after he has carried out that project and proved the successful working of his system, we will ask him to come over and give us a paper on the general subject. A hearty vote of thanks was accorded to Mr. Preece for his communication, and also to Mr. Van Rysselberghe for his remarks and for his promise of further information. A ballot for new members took place, at which the following candidates were elected : : |