348 



MEMOIR OF DANIEL TREAD WELL. 



slow from being performed in capillary vessels of extreme minuteness, so that very small 

 points of the different fluids can be brought in contact- From these circumstances, a period of 

 some years is required for the sufficient docking of oak and other solid woods- . . . 



ffice) and the apparatus connected with it. . . . 



( 



" A piece of dry ash three inches in diameter and fourteen inches long was fixed to the 

 forcing pump, so that a small part of one end was presented to the fluid as it was forced from 

 the pump, the other part of the wood being open and in the atmosphere- A pressure of four 

 hundred pounds per inch made the water immediately to run in a stream from the end opposite 

 to that in contact with the pump. . . . 



" The same repeated, with a piece of solid green oak. The water was forced through with 

 the same pressure in two minutes, making its appearance by oozing, rather than in a distinct 

 stream. In both, these specimens gained one ounce each in weight by the injection." 



Several other experiments were tried with a similar result. Considering it as 

 sufficiently proved that timber may be filled with a fluid in a very short time, if 

 subjected to a pressure of forty or fifty atmospheres, Mr. Treadwell proposes that 

 the government should adopt the method. It is not known that this communica- 

 tion received any reply ; the suggestions were certainly not adopted. The plan 



was successfully used ten years after by French engineers.* 



About this time, (1823,) Mr. Tread well's advice was asked as to a question of 



hydraulic engineering, the result of which shows well his method of reasoning and 

 his ready resources. A leaden pipe, an inch and a half in diameter and about six 

 thousand feet long, had been laid to supply water for the families of the workmen of 

 the Mill-dam manufactories. It was laid principally in a marsh, and ran beneath the 

 bed of two creeks about twelve feet deep each. The end of the pipe at its outlet 

 was about four feet below the level of the source. When completed, not a drop of 

 water would run through it. 



" In this state of things I was requested, by those interested in the aqueduct, to consider the 

 circumstances, and endeavor to procure a passage of the water. When the exact condition of 

 the aqucduet was taken into consideration, I perceived that the water let into it might have 

 made such an arrangement in relation to the air with which the pipe was previously full, as 

 to obstruct wholly its passage. For let us suppose, in the annexed figure, A B to represent a 



* A process of injecting corrosive sublimate was reported by Kerausdren, in 1839. Kyan also devised a 

 process called Kyanizing for injecting the same substance; since 1848 it has been used in this country, and found 

 to be very effective. In a letter on these various processes, James B. Francis, Esq., of Lowell, states that, 

 " about forty years ago, Bethel devised the process called creasoting, in which a fluid derived from the coal tar of 

 the gas works is injected. This is very generally used in England for the preservation of railroad ties, and is 

 considered very efficacious." Various other methods for the same object are now in use in Europe and in this country. 

 See "Meinoires Ponts et Chaussees " Vol. XL, 1836 and 1843. 



