Having reached this stage our builders can now take large orders much more cheaply than a few years since, and which in 1887 they could not have taken at all had it been required to supply all parts from our own industrial establishments. This fact, taken with the dawn of a new era in our commercial relations, wherein the ship-owner will have a fair chance of carrying both ways, gives good prospect of an early rehabilitation of our ancient power upon the sea.
[1] Report of Lecture in the Liverpool Albion, delivered in Liverpool, December, 1835.
[2] The account given of the Savannah is condensed from Admiral Preble’s Notes for a History of Steam Navigation.
[3] Daniel Dod, an American citizen, was granted a patent November 29, 1811, in which he states: “I form the condenser of a pipe or number of pipes condensed together; and condense the steam by immersing the pipes in cold water, either with or without an injection of water.”
The present surface condenser consists essentially of a great number of small brass tubes, about three-fourths of an inch in diameter, passing through an air-tight chamber. The exhaust steam from the cylinders enters the chambers, and cold water is constantly pumped through the tubes. The steam is condensed by contact with the cold tubes, and the water thus obtained pumped back to the boiler in a fresh state, instead of being mixed with about thirty times its weight of salt water, as in the old jet condenser. Practice varies, the steam sometimes being passed through the tubes and the water around them.
[4] The Naval Chronicle of 1818, vol. xxxix., p. 277, speaking of the steamers on the Clyde, says: “No serious accident has occurred since their introduction, which is more than two years. The secret of security consists in using large steam-engines of great power and small pressure. If the boilers of cast-iron should in any part give way, a piece of cloth is firmly wedged in the hole, and the vessel proceeds without any danger or inconvenience to the passengers.”
[5] Compiled from official data in Engineering, June 19 and July 10, 1891.
[6] A fuller discussion of this subject is given in the chapter on “Safety on the Atlantic.”
[7] This is as shown by Lloyd’s Register, 1891-92; the official returns, dealing with the official year, give 609 vessels and 537,605 net tons; our own net tonnage is about 74 per cent, of the gross shown.