PACIFIC RAILWAY, PRINCE RUPERT, BRITISH COLUMBIA. 229 
dock had been lowered to its greatest working depth; that is, the depth which would 
take over the keel blocks, the greatest draft for which the dock was designed. ‘This 
resulted in providing the extra ballast amounting to about 375 tons, in the form of 
timber (see Plate 114) to be placed in the wings upon the flooring about 7 feet 
below the top. The displacement of this amount of timber will represent about 650 
tons and, of course, its submergence by the sinking of the dock would increase the 
displacement to this amount, and if the necessary weight to sink the dock was only 
375 tons, all of this displacement would be reserved buoyancy, and it would be 
practically impossible to cause the dock to sink entirely. 
It will be seen that this security would depend upon the nature of the material 
used and not at all upon any structural feature. In other words, the dock might 
be injured in any conceivable manner and it would still be impossible to entirely 
submerge it. 
THE PRESIDENT:—Is there any further duscussion? Any other questions to 
ask? If not, I will extend in your behalf the thanks of the Society to Messrs. Kirby - 
and Donnelly for their admirable paper, and we will pass to the next paper, 
entitled “‘Heavy Oil Engines for Marine Propulsion,’’ by Mr. G. C. Davison, 
Member. In the absence of Mr. Davison, the paper will be read by Mr. Reid. 
Mr. ReIp:—I would be very much better pleased if Mr. Davison had turned 
up to read his own paper. I am instructed to curtail the paper, and may leave 
out the matter which he would wish to emphasize. However, I will do my best. 
Mr. Reid then abstracted the paper. 
