60 



ANNUAL OF SCIENTIFIC DISCOVERY. 



STRENGTH OF WOODEN WATER-PIPES. 



The Scientific American publishes the following report of a series of exper- 

 iments concliuk-d by Israel Marsh, Esq., of Rochester, N. Y., with a view of 

 determining the strength of wooden water-pipes to resist hydraulic pressure. 



Pipes of various sizes were subjected to pressure so great as to burst them, 

 but they bore a far greater amount than any spectator supposed them capa- 

 ble of bearing. The largest pipe tested had a bore of eight inches in diame- 

 ter; the smallest had a bore of one inch and five-eighths through a pine 

 scantling of three and a half inches. These scantlings were put together in 

 sections, and sustained a pressure equal to a head of one hundred and 

 eighty feet, and subsequent experiments showed that they would sustain a 

 far greater pressure before bursting. 



The following is the report of Mr. Marsh, regarding his experiments ; and 

 the results, as placed in a tabular form, will be found very convenient for 

 future reference by hydraulic engineers and others : 



Hydrostatic pressure was applied to the pipe by means of a double-acting 

 piston-pump, with an air-chamber attached; and the amount of pressure 

 acting upon the whole interior surface of the pipe was ascertained by means 

 of a piston, which was cylindrical in form, and made equal in area to one 

 square inch, and fitted to an opening in the pipe, which conveyed the water 

 from the pump to the wooden pipe, and of a scale-beam graduated so as to 

 indicate any amount of pressure from forty to two hundred pounds. The 

 opposite side of the beam was graduated to indicate in feet the height of a 

 vertical column of water, which would produce a corresponding pressure. 

 Some of the pipes used in these trials were made of round logs, and others 

 of square scantling; but they were all made of Avhite pine timber. The fol- 

 lowing is a statement of the pressure to which the pipe was subjected, in 

 which the last column indicates the pressure at which the pipe burst: 



WORK OF WATER-WHEELS BY NIGHT AND DAY. 



The following note, on the above subject, has been addi-essed to the editors 

 of the Scientific American, by a correspondent in East Pepperell, Mass : 

 In the course of my business of building and putting in water-wheels 



