PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 525 



The iron-clad Galena has not been heard from since her maiden effort on 

 the James River. If her ventilation was not good when she went into ac- 

 tion, it was so when she came out. The Keokuk had a short, but brilliant 

 career. The Roanoke is said to be top-heavy, and therefore unfit for sea, 

 and she draws so much water that she can enter but few of our harbors. 

 The Ironsides has no speed, and cannot be steered, and she completes the 

 list of failures. Our wooden ships-of-war are notoriously slow, yet we must 

 remember with pride their capture of New Orleans', where the conflict was 

 with formidable earth works, and of Port Royal, where the gallant Dupont 

 formed his fleet into a crescent battery, and gave a salute from a new po- 

 sition each time he circled around, as it were, in a triumphant procession, 

 which, if attempted by our iron-clad fleet, would more resemble a funeral 

 procession, from its minute guns — a contrast that must have occurred 

 promptly to the gallant Admiral, when he wag condemned to the command 

 of the iron-clad fleet in Charleston harbor, where he was unable to take ad- 

 vantage of another wonderful creation of the great Ericsson, the Devil, be- 

 cause the Monitors, so far from being able to shove so heavy a drag before 

 them, were unable oven to make headway against the tide. 



If the qualities enumerated at the beginning of this argument are really 

 essential to effioiency in iron-clad ships, how sad it is to reflect that not 

 one of our boasted fleet comes up to the requirement in a single particular. 



The Manufacture of Tin-lined Lead Pipe. 



The subject for the evening was here taken up, when Messrs. Willard 

 and Shaw, of the New York Lead Company, 63 and 65 Centre St., exhibited 

 a large drawing of their method of making patent tin-lined lead pipe. Mr- 

 Shaw said — We make this pipe in lengths of fifty to sixty feet with one 

 charge, but, if necessary, we could make it a mile long. The lining is of 

 pure tin without any alloy. The tin unites perfectly with the lead pipe* 

 This tin-lined lead pipe can be worked as readily as the common pipe, and 

 is as cheap as it, when we take into account its extra strength which 

 enables us to make the pipe a little thinner and brings the cost down to the 

 lead pipe, as it is by the weight the pipe is sold. We make a uniform 

 coating of tin inside the pipe and all parts will have the same percentage 

 of tin throughout. We claim the formation of a tin and lead pipe at the 

 same operation. Block-tin pipe is objectionable on account of the difficulty 

 the plumbers have in soldering it. When making the pipe the tin and lead 

 are very near the melting point and when forced through the press unite 

 perfectly. 



Mr. Nash. — In regard to the deleterious effect of using lead pipe I can 

 say that if I let the water stand in the lead pipe in my house for an hour I 

 can instantly perceive the taste of the lead in the water, and I now never 

 use the water without first letting it run till I know it comes from the iron 

 pipe in the street. 



Chairman. — This question of the effects of lead pipe on the water passing 

 through it is a most important one. It has been decided by some chemists 

 that there is no injurious effects from its use, as the water unites with the 

 lead forming a thin coating of the carbonate of lead, which is insoluble in 

 water. While on the other hand we have a number of opinions quite the 



