328 



FEENCH EXHIBITION. 



and following, southward, the line traced out 

 for the canal toward Damietta, we come to 

 the lagunes of Menzaleh, about twenty-five 

 miles long, separated from the Mediterranean 

 by a strip of beachj which runs out shoal for a 

 considerable distance into the sea. The Medi- 

 terranean mouth of the canal is cut through 

 this strip ; and here, situated eighteen miles 

 west of Pelousa, is Port Sa'id, created by the 

 company to be their base of operations, and 

 where are established considerable workshops 

 for the maintenance and repair of plant. 



After leaving the lagunes, the Hue of the canal 

 cuts through a strip of sand about 4 miles wide, 

 elevated about 4 feet above the sea ; this strip 

 separates the lagunes of Menzaleh from those 

 of Ballah, the width of of which is 14 miles. 

 Then occurs the elevated plateau of El Guisr, 

 the highest ground between Pelousa and Suez; 

 through this the canal is carried in a very con- 

 siderable cutting nine miles and a half long, with 

 a maximum depth of 55 feet. After crossing this 

 plateau a depressed plain is reached, called 

 Lake Timsah ; the lowest level of this plain is 

 19 feet below the water of the Mediterranean. 

 The line then crosses a second elevated plateau, 

 called Serapeum, 46 feet above the level of the 

 Mediterranean, and nine miles long. South of 

 this lie the lakes of Amer, two shallow lagunes 

 separated by a narrow strip of sand. Meantime, 

 across them water communication is obtained 

 by admitting the water of the Mediterranean 

 into Timsah, and the Eed Sea into Amer, thus 

 transforming them into navigable inland seas. 

 Beyond the lakes of Amer is the raised ridge 

 of Ohalouf, 26 feet above the level of the sea, 

 the southern slope of which forms the plain of 

 Suez, elevated 6 feet 6 inches above the sea- 

 level. .After crossing this plain, the lagune of 

 Suez is reached, which communicates by a 

 shallow inlet with the Red Sea. Thus the total 

 length of the canal is about 100 miles, of which 

 37 miles is in cutting, whilst 63 miles are at or 

 beneath the sea level. 



The first work undertaken by the company, 

 preliminary to their main work, was the exten- 

 sion, as far as Lake Timsah, of the old fresh-water 

 canal, which, starting from Moes, wound east- 

 ward, past Abassieh to Ras-el-Ouady. This 

 'extension gave them means of transport for 

 their provisions and materials from the Nile 

 into the very heart of the isthmus, a supply of 

 water for their workmen and for their engines, 

 and enabled them to establish their central 

 depot of Ismailia. 



The general dimensions of the maritime canal 

 are : width of water level in embankment, 328 

 feet; ditto in cutting, 190 feet; width at bot- 

 tom, 72 feet; depth, 26 feet 3 inches; the bat- 

 ter of the sides varies with the nature of the 

 soil, the steepest slope being about 2J to 1. 



America exhibits but a few specimens of her 

 engineering skill. A bold engineering scheme 

 for the supply of water to the city of Chicago, in 

 Illinois, is recorded upon a plan hanging against 

 the west wall in the United States section. 



A good example of the application of wood 

 to bridge construction will be found in a model 

 jVth full size of a wooden railway swing-bridge 

 which has recently been constructed in the 

 State of Ohio. Each opening has a clear span 

 of 150 feet; the diameter of turntable is 30 

 feet; length of bridge over all, 335 feet; the 

 depth of the truss is 10 feet at the ends, and 34 

 feet at the centre. The arched part is composed 

 of four timbers, 10 inches by 6| inches ; main 

 struts, 14 inches by 8 inches, extend to each 

 side from the turntable to give support to the 

 arched top, which is further strengthened by 

 three straining-pieces, 8 inches by 10 inches. 

 The chord consists of four 12 inch by 6^ inch 

 timbers, and is put together with a camber of 

 about 6 inches. The weight of the bridge is 

 200 tons. 



Electricity. If it were possible to bring into 

 bird's-eye view the various electrical apparatus 

 exhibited at the Exhibitions of 1851,-'55,-'62, 

 and '67, great advancement would be shown. 

 It is now exhibited, not only as applied to tel- 

 egraphy, but to an inconceivable variety of 

 purposes regulating trains on railways, and 

 dividing time into the 200th part of a second ; 

 fusing bars of iron, and producing the finest 

 line engravings ; establishing communication 

 between the passenger and the guards of the 

 train, etc., etc. ; but the progress made from 

 1862 to the present is not nearly as striking as 

 that between the previous displays. In the 

 construction of telegraphs in France the poles 

 are very slight, and without stay or strut. In 

 England, on main lines, it is the exception 

 to see a pole without the one or the other. In 

 France the wires are placed at least 20 inches 

 apart. In England the space rarely exceeds 10 

 inches, with 20 wires on the same poles, which 

 the strongly-constructed posts can well sustain. 

 They both use No. 8 iron. 



The insulators are various, and the French 

 administration have commissioned M. Gaugain 

 to investigate the subject of insulators. The 

 French, however, have only an imperfect sys- 

 tem of electrical measurement. Their unit of 

 resistance is one kilometre of iron wire, four 

 millimetres in diameter; but they appear to 

 have no fixed standard, and as iron varies so 

 much in its quality, and the resistance varies so 

 much with temperature, it is impossible to get 

 two results alike. The French kilometre would 

 be a very convenient unit, if .properly, deter- 

 mined, because at some temperature between 

 10 C. and 30 0. it is exactly equal to 10 ohms 

 or B. A. units, and it would remedy the princi- 

 pal objection to the British unit, viz., its minute- 

 ness. 



There are instruments transmitting intel- 

 ligence in clear Roman type imprinted on 

 paper; instruments in which the letters of 

 the alphabet are permanently depicted by 

 arbitrary symbols, either printed or embossed ; 

 instruments which temporarily record their sig- 

 nals by the movement of an index over the 

 face of a dial, or the simple movement of a 



