Tod and Macgregor were the foremost in screw steamships--those for the Peninsular and Oriental Company being splendid models of symmetry and works of art.

Some of the fine wooden paddle-steamers built in Bristol for the Royal Mail Company were sent round to the Clyde for their machinery.

I contrived to board all these ships from time to time, so as to become well acquainted with their respective merits and peculiarities.
As an illustration of how contrivances, excellent in principle, but defective in construction, may be discarded, but again taken up under more favourable circumstances, I may mention that I saw a Hall's patent surface-condensor thrown to one side from one of these steamers, the principal difficulty being in keeping it tight.

And yet, in the course of a very few years, by the simplest possible contrivance--inserting an indiarubber ring round each end of the tube (Spencer's patent)--surface condensation in marine engines came into vogue; and there is probably no ocean-going steamer afloat without it, furnished with every variety of suitable packings.
After some time, the Messrs.

Thomson determined to build their own vessels, and an experienced naval draughtsman was engaged, to whom I was "told off" whenever he needed assistance.