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PACIFIC CABLE COMMITTEE:

Enclosure in No. 5.

Teredo Faults in over 100 Fathoms Depth.

Porthcurnow-Lisbon, No. 1-

Lisbon-Gibraltar, No. 1 Lisbon-Gibraltar, No. 1 Zante-Canea

·

·

Sawakim--Aden, No. 2

260 fathoms (smooth).

430-380 fathoms (mud).

596-755 fathoms (stiff clay).

840-1,050 fathoms (clay).

27-280 fathoms (coral; mud in deeper water).

No. 6.

The COMMERCIAL CABLE COMPANY to MR. MERCER.

DEAR MR. MERCER,

Bishopsgate House,

55 and 56, Bishopsgate Street Within, London, EC., December 4, 1896.

WITH regard to Questions 1628-35, we reckon, taking an average, that 16 per cent. of the total number of letters transmitted is dead work, that is to say, work used for service purposes and not paid for.

*This, of course, refers to ordinary messages and not to

press

work.

Yours, &c.

FREDK. WARD,

Manager in England.

No. 7.

THE AGENT-GENERAL FOR SOUTH AUSTRALIA to LORD SELBORNE.

DEAR SIR,

Office of Agent-General for South Australia,

1, Crosby Square, Bishopsgate Street Within, London, E.C.,

December 15, 1896.

ACCORDING to promise, I telegraphed to Sir Charles Todd, desiring him to furnish me with

a statement showing the receipts on account of the Port Darwin line of telegraph for each of the last five years, and the average working expenses for the same period.

The following is the reply

-

"International receipts five years ending April 1896 :---

DEAR LORD KELVIN,

CORRESPONDENCE.

No. 8.

LORD SELBORNE to LORD KELVIN.

Colonial Office, December 16, 1896. My colleagues on the Pacific Cable Committee and myself will esteem it a great kindness on your part if you will consent to answer in writing the following questions arising out of the evidence given before the Committee. On December 24, 1895, Mr. Matthew Gray, Managing Director of the India-rubber, Gutta-percha, and Telegraph Works Company, writes to Sir Charles Tupper as follows:—

In a report which Lord Kelvin has furnished us with, we find that he recommends for the " section mentioned aboro" (Vancouver to Fanning Island) "a core of 552 lbs. of copper and "368 lbs. of gutta-percha per nautical mile, to give 12 words per minute over a length of "3,560 nautical miles."

The questions we should like to have answered are:-

1. How many letters per minute did these 12 words represent?

2. Were these letters the maximum number obtainable per minute, from such a core, over such a distance, the theoretical speed in fact, or were they the number of paying letters which could actually be obtained per minute, the practical speed in fact?

3. In either case did you mean that that speed could be obtained by the automatic curb process of transmission or by the ordinary process of transmission? and if the latter, what difference to the calculation would the use of the automatic curb process make?

4. Could the automatic curb process be used on a cable from Vancouver to New Zealand and

Queensland vid Fanning Island, Fiji, and Norfolk Island?

Cur reason for asking these questions is that Dr. Muirhead has stated in evidence that by the use of the automatic curb process of transmission a speed of 80 letters per minute (simplex) could be obtained from the core in question over the above-mentioned section. He has further written to say that this result as to speed of transmission obtained by him on an artificial cable in his laboratory has been exceeded in practical tests on cables with code traffic, and that therefore this opinion may be considered as a perfectly safe one, as the speed of cables depends upon the product of the total capacity of the core and the total resistance of the conductor, not upon the mere length of the conductor, and that such signals as are given by this speed of transmission are such as can be safely and readily read by an average operator.

Believe me, &c.

SELBORNE.

PUBLIC RECORD OFFICE

Reference :-

TTIC.O. 885

www.il

6

PUBLIC RECORD O

ALLY WITHOUT PER BE REPRODUCED P

COPYRIGHT PHOTOGRAM

1891

1892

1893

1894

1895

Total

£

27,137

29,877

36,730

36,428

43,807

173,979

"Or average 34,796., exclusive of guarantee payments which amounted in five years 17,7961.

"Average receipts from local traffic, 2,5451. "Average working expenses and interest, 45,290."

to

Adding one-fifth of the receipts from guarantee payments, and the average receipts for local traffic, makes the total average receipts of the five years 40,8901. The average expenses being 45,290l. shows an average loss of 4,3901. a year.

The Hon. Dr. Cockburn, at the Sydney Postal and Telegraphic Conference, 1896, intimated that "South Australia is willing to join in the project provided that a guarantee, either from the con- tributing colonies alone, or jointly with the Imperial Government, be given that the financial " position of South Australia as regards the Port Darwin line be maintained on the basis of the

average of the last five years."

"

Now that I see the figures, it appears plain that the * basis of the average of the last five years must mean the average working expenses and interest, and not the average receipts—that is, the guarantee is to make up the receipts to 45,290l. a year if they fall below that sum in consequence of the competition of the Pacific cable otherwise the Colony would be liable to a loss of 4,3907. a year, which I feel sure the Government never contemplated; for in their communications with me they have definitely, and on more than one occasion, said that "the Government were willing to

join in laying a Pacific cable if loss on Port Darwin line was made good.”

"

DEAR LORD SELBORNE,

No. 9.

LORD KELVIN to LORD SELBORNE.

The University, Glasgow, December 18, 1896.

IN answer to a question from Mr. Matthew Gray I reported that, with weights of copper and gutta-percha 5527 and 368-5 lbs. per nautical mile in a cable of 3,560 nautical miles length, "the highest speed attainable by the best modern instruments and operators up to the present date" (November 5, 1895) would be 12 words per minute of an average five letters per word. I do not think it would be safe to reckon on a higher speed for practical signalling even with the best automatic curb-key for transmission, At the same time I think it quite possible that, as stated by Dr. Muirhead, 16 words (80 letters) might be transmitted and read, especially when we consider that, for such slow rates of signalling as 12 or 16 words per minute, the instrumental difficulties are much less than at the higher speeds of from 25 to 50 words per minute, on which our experience of practical signalling through submarine cables is chiefly founded. I could not at present advise any company to reckon on more than 12 paying words per minute for the quantities and length referred to and with only gutta-percha of quality at present realised. gutta-percha of smaller inductive capacity, or with other insulating material of smaller inductive capacity than the gutta-percha on which I reckoned, a higher speed than the 12 words per minute might be attained in a cable of the same linear dimensions and practically the same weights.

The automatic key, whether curb or not curb, could certainly be used with advantage at all the stations between Vancouver and New Zealand.

With

Yours truly,

KELVIN.

I am, &ct

The Right Hon. the Earl of Selborne,

T. PLAYFORD.

Chairman, Pacific Cable Commission.

* This is because the press telegrams are very much longer, and therefore the per-centage of dead work is very much less.

W. H. M.

4/19/96.