WCP3171

[1]¹

Uig Isle of Skye

Sepr 16th 1898

My dear Sir

Since your letter² reached me I have been touring about & not been able to write to you at length on the interesting subject to which you refer[.]

I may say that the subject of carrying fast ships on some form of oblique plane surface or numerous such surfaces has received some attention for a considerable time than people generally suppose[.]

[2] The Count de Lambert³ of Paris has patented the idea and his specific arrangement of multiple planes of shutters or the leaves of tables [sketch] set at about 5° angle to the direction of suction, this angle being adjustable & I have seen a small double skiff made for him by Mr Phillips⁴ of Harrow (of flying machine fame) weighing altogether with the attendant 600 lbs developing about 10 I.H.P. & travelling about 20 miles (land miles) per hour.

I was lead by calculation to think that about the same speed would be realized with an ordinary hull ^{& with} of the same weight & H.P.

He has so far made no very accurate determinations as to the coefficient of resistance[.]

[3] He also tried a wide flat bottomed ship of larger size (somewhat like you describe & propose) with extremely light engines of 300 H.P. but the result was a failure and the boat could not be got to mount ^on to the surface -

Maxim (Hiram)⁵ patented the idea some 4 or 5 years ago but as far as I am aware he's obtained no practical results.

Several German gentlemen have written to me during the last 2 years, sending many drawings & calculations[.]

My own conclusion has been as follows & I may state it for what it may be worth carrying ships on planes if successful can only be applicable to ships of small size & fast speed, it may enable such [4] to reach very great speeds in smooth water.

It cannot ever be used for ships of say 5,000 to 10,000 tons just as a bird of ordinary construction of flesh & feathers but 1 ton weight could not fly[.]

Ships of 5,000 — 10,000 — 20,000 tons are carried with much less resistance when borne by their displacement up to speeds of 30, to 60, knots per hour.

The Livadóa built for the Emperor of Dresden was flat bottomed & nearly [illeg.] in the Bay of Biscay by ^the striking of her flat bottom on the [illeg.] which stone in parts — & she was afterwards condemned.

It is a very interesting subject & I am very much obliged to you for writing to me on this subject. It is quite [illeg.] that developments may take place but it will be first [5]⁶ with ships of small size. In regard to the canal boat, possibly the canal was narrow & shallow & it would I think scarcely be safe to conclude that the superiority of the flat bottomed boat would hold good in open water[.] Also possibly the form of the ordinary boat with which it was compared may have been unsuitable for the size, depth, & speed.

[6] In regard to creating screws at an angle — In the first place the upward component of the thrust is in all cases a very small force compared with the height of the ship.

even [sic] in the Turbinia it does not exceed 1 p^sf & the effect on the trims or its lifting power is almost inappreciable -

[7] I wish I could ^have fallen in with your suggestions — but you will see that they have already been the subject of some not very [illeg.] investigation — & perhaps Prof Langley's⁷ experiment & those of Mr Maxim & Mr Phillips represent the best works on this subject[.]

You have doubtless read the formers works on the flight of birds & his coefficient of resistance of planes moving [8] at high velosity through the air[.] All mathematicians from Rankin till a few years ago gave wrong coefficient untill Langley's ^{& another's} experiment gave the actual forces as observed by accurate experiment.

With my kind regards

Yours very truly | Charles A. Parsons⁸ [signature]

Alfred R. Wallace Esq