G.—ENGINEERING. 121 
to be surmounted. In the case of turbines certain of these difficulties were 
“non-existent, and turbines are peculiarly suited to the use of superheated 
steam. 
Another economical advance is pre-heating of air, which is now being 
pushed much further than ever, but with which the name of Howden will 
always be associated. Stage feed-water heating is also being very fully 
carried out, which you will hear of in detail from Mr. Stanley Cook. 
Fuel-oil firing of boilers has been very largely adopted in steamships, 
with a marked gain in speed and, when oil is marketed at certain figures, 
with economy of cost as compared with coal, not only on account of its 
relatively smaller weight consumption, but on account of the reduced 
crew required and the more regular speed obtained, hence shorter time at 
sea. But in considering the relative advantages of steam- and motor- 
driven ships one must remember that an oil-fired steamship, in the event 
of oil soaring in price, may be converted to coal-burning, while in a 
motor-ship the owner has not that option. 
As to powers developed by the main engines in any one steamship, 
from the 2-3000 I-H.P. in good-class passenger-ships of 1875 to the 
75,000 I H.P. we now find in the most powerful merchant-ships, or of over 
140,000 in naval vessels, is a stupendous step. 
As a matter of interest—in the course of my inquiries the first twin- 
serew vessel I can trace was a 60-ft. craft built for the Khedive of Egypt 
by Rennie of London in 1854; Dudgeon built the Far East in 1863; 
the Admiralty fitted twin screws in the Penelope in 1867, and the 
Notting Hill appears to have been the first North Atlantic twin-screw 
steamer, built in 1881 ; but vessels so fitted were not usual till the middle 
eighties. Although multiple screws had been fitted—e.g. in the Livadia— 
four and three shafts seem to have come into more general use with the 
turbine. The combination of twin screws driven by reciprocating engines 
with one or two other screws driven by turbines taking the exhaust 
from the reciprocating engines, was a step between direct-drive turbine 
and the introduction of turbines with gearing, when twin screws were 
generally reverted to. 
I have to confess that this fifty years’ survey of marine engine-room 
and boiler-room development is so brief that it cannot do justice to the 
subject nor to those who have been responsible for the advance made 
during that period, but I think the salient features have been touched 
on in sufficient detail to show you what the engineers of this country have 
done for marine engineering. 
Turning now to the ship herself and to naval architecture—after 
erving three years as an apprentice in the yard, and spending another 
bree years at the Royal Naval College, Greenwich, as a private student, 
rough the kindness of Lloyd’s Register I was received at the Liverpool 
Office as an ‘ observer ’ (to use an American term), or, as my late brother, 
Villiam Denny, said, ‘as a volunteer surveyor to study the morbid ana- 
omy of shipbuilding.’ The severe North Atlantic storms were the most 
trying to ships, and at Liverpool one had the opportunity of seeing the 
‘Breatest number of damaged hulls. It was a most valuable experience, 
at that time the transatlantic steamers were developing rapidly in size, 
d many of them were sorely tried and damaged in their superstructures. 
I crossed to the States to see ships’ behaviour in heavy weather in 
ecember of 1882 in the Parisian, of the Allan Line, and returned in 
D 
