92 ANNUAL OF SCIENTIFIC DISCOVERY. 



both the number and weight of the anchors was increased. Those 

 now put on were but five feet apart instead of nine feet ; and the weight 

 of each one was 34 instead of 28 Ibs. The line being thus prepared, 

 a steam tow-boat, properly fitted with bitts in the stern, was made fast 

 to the hawser, at a distance from its upper end equivalent to the width 

 of the river. Just before the slack of the flood-tide, the lower end of the 

 hawser was cut loose from the anchor which had kept it stretched, the 

 end taken on board the steamboat and made fast to the bitts, and the 

 movement across the river commenced. The hawser, notwithstanding 

 the weight of anchors upon the pipe, was still kept extended by the 

 power of the steamboat, and the whole line swung round on its centre, 

 until it stretched across the river to the New York shore; when the steam- 

 boat was sufficiently near the proper point of that shore, the bite of the 

 hawser was run ashore by a heaving-line, slipped into a large snatch- 

 block, (which had been previously attached to the solid rock just above 

 high- water mark,) the rest of the bite cast loose from the steamboat, 

 and she getting again under headway, the hawser was drawn taught 

 through the snatch-block, and every boat was brought up in a perfectly 

 straight line. From the bows of this line of boats the pipe now 

 hung immediately over its destined bed. The line which suspended it 

 to each boat passed over a chopping-block a man stood by with a 

 hatchet, and when the word was given, a single blow from each man 

 let the pipe drop to its place. There is but little doubt that it is prop- 

 erly placed, and but little fear that it will fail. It perhaps may be 

 as well to mention here, that the first attempt to put down the pipe in 

 this manner failed. The power of the steamboat was, of necessity, 

 applied in a direction tangent to the arc which she would describe 

 while performing her work. The difficulty of doing this, while so 

 great a weight at her stern was counteracting the power of the rudder, 

 was found to be much greater than was anticipated, and the ebb-tide 

 making when the steamboat had reached about half way across the 

 river, she, together with the entire line of boats, was swept back to 

 the shore whence she had started. The operations at the slack of the 

 flood-tide next day were successful, and the time occupied was twenty 

 minutes. 



From this experiment, partly induced by a desire to obtain profes- 

 sional knowledge of a new material, partly forced by the difficulties of 

 the locality, such results as have been determined may be considered 

 satisfactory. Its flexibility and lightness, and the consequent ease and 

 economy in handling it, certainly proved great advantages in the work 

 here detailed. Its specific gravity is about 98, and its flexibility suf- 

 ficient for its close adaptation to a very uneven and irregular bed. 

 Under the hydraulic press, also, the pipe was found to be slightly elas- 

 tic, and to this may be attributed the success with which the line bore 

 the pressure to which it was subjected during the winter. The pres- 

 sure of the Croton at this point is (in a state of rest) about 45 Ibs. to 

 the square inch ; but in view of the sudden strain often occasioned by 

 the too rapid shutting down of a stop-cock, the iron pipes are always 

 subjected to a test-pressure of 300 Ibs. During the winter, a stop-cock, 

 on the lower end of the island, was broken from this cause, although it 



