104 ANXUAL OF SCIENTIFIC DISCOVERT. 



Iviiio: oft' Sheerness. This section is of 3 kinds, namclv, 1. 

 Tlu! lieavy shoro-ends for protection jigainsL ships' anchors, 

 tiiles, etc., weighing 3G0 cwt. per mile. 2. The "interme- 

 diate," of a size between the shore-end and the deep-sea por- 

 tion, 127 cwt. per mile. 3. The deep-sea portion already 

 described. 



The whole of the above, 2,788 knots in length, with the excep- 

 tion of loi miles of shore-end, and 20 miles of intermediate, was 

 taken to the Great Eastern. We calculate that if the various 

 component parts of it were laid end to end, they would make a 

 chain of over 102,000 miles in extent, or nearly 8 times the cir- 

 cumference of the globe. The whole of the work, including the 

 manufacture of the two sections, and the fitting out of the Great 

 Eastern, occupied little more than 8 months. 



For the accommodation of the cable on board the Great East- 

 ern, 3 gigantic tanks were constructed, situated in the centre, 

 stern, and fore part of the ship, and known as the main, after, and 

 fore tanks, respectively. Their diameters were as follows : 

 Fore, 51 feet 6 inches diameter, by 20 feet C inches deep ; main, 

 75 feet diameter, by 16 feet 6 inches deep ; after, 58 feet 

 diameter, by 20 feet 6 inches deep ; with a total capacity of 

 1G9,7G0 cubic feet, — being 27,750 feet greater than the capacity 

 of the tanks in 1866. Tiiese immense structures were fixed to 

 the sides of the ship, and supported by about 30,000 cubic feet of 

 timber. The weight contained in them was about 5,520 tons, dis- 

 tributed as follows: Fore, 1,270 tons; main, 2,580 tons; aft, 

 1,670 tons; total, 5,520 tons. 



Tlie cable paying-out apparatus, consisting of an elaborate 

 series of brake-wheels and stoppers, with the measuring-machine, 

 and the "dynamometer," a machine constantly recording the 

 strain on the cable, contained all the improvements that science 

 and experience have suggested. The dynamometer especially 

 claims our notice, as being, to our mind, one of the most ingen- 

 ious and useful contrivances connected with the apparatus. It is 

 placed between the stern of the ship and the paying-out brakes, 

 and consists of a vertical framework of iron, in tiie centre of 

 which is fitted a grooved wheel, for the cable to pass under as it 

 runs out over the stern of the ship. The wheel is made to slide 

 up and down the frame as the strain on the cable varies, or, in 

 other words, as the cable becomes ti^'hter between the stern 

 and the brakes. At the side of the machine is a scale, with the 

 calculated strains in hundred-weights marked uj)on it ; and a hand 

 fixed to the sliding-wheel traverses this scale, and indicates at 

 anv moment the strain on the cable. From the indicated strain, 

 of course, the depth of water may be judged, and the brakes 

 arranged accordingly ; but the dynamometer is of most service 

 in cases of hauling back the cable. 



The ship was also fitted with a powerful set of pieking-up 

 machines and tackle, together with buoys, buoy-ropes, musjiroom 

 anchors, and everything requisite for picking up the cable in case 

 of a breakage, asin 1865. 



We must not forget to mention that the ship was also fitted 



