End Notes: The Developement of the Steamship
Note 519-A: Report of Lecture in the Liverpool Albion, delivered in Liverpool, December, 1835.
Note 520-A: The account given of the Savannah is condensed from Admiral Preble's Notes for a History of Steam Navigation.
Note 535-A: 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 on inch in diameter, passing through an air-tight chamber. The exhaust steam from the cylinders enters the chamber, 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.
Note 535-B: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."
Note 537-A: Mr. W. John, in a paper read before the Naval Architects, in June, 1S86.
Note 541-A: The figures for these three posts are exclusive of the tonnage built on foreign account.