34 AXNIJAL OF SCIENTIFIC DISCOVERY. 



In mnny places in Eiifrlaiul, a plan not unlike that by which the 

 valley of tlie Kile is made fertile, is carried out. In Yorkshire, 

 for example, it is a regular practice to open the banks of the 

 Dutch river, and allow its turl)id waters, which contain nnich soil 

 in suspension, to spread over tlie ticdds. When the j^aj) is closcid, 

 and the water drawn off, a rich alluvial mud remains, on which 

 splendid crops are raised. The system of openin;^ the l)anks of 

 tiu! river is, however, awkward and expensive. Tlie Suez canal- 

 dredu:e does away with its necessity, and a])plies scienlitically 

 what is now obtained by a very clumsy system. — London Slur. 



The i\Ialta "Observer," of a late date, says: "By reliable infor- 

 mation, recently received, we learn that the works of tln^ Isthmus of 

 Suez Canal are beinf>^ very actively carried forward by M. de Les- 

 seps. An averaj^e dejith of from seven to nine feet has been ob- 

 tained from I'ort Said, along the salt-water canal ; and the rest of 

 tlie distance to Suez is traversed temporarily by a fiesh-wat(u* one 

 about seven feet deep, connected with the other by means of locks 

 and powerl'ul pumps. As far as sixty stations the full width of 

 the projiosed ship-canal has been excavated to sixty metises ; but 

 from that point to the seventy-fit'th station and Ismalia, the width 

 is iiicom])lete. All that has been done is done well, and relleets 

 the highest credit on the science, skill, and persevering energy 

 of the French engineers. The real dillieulties of dredging in a 

 constantly dissolving sand are now commencing; but well in- 

 formed jjcrsons entertain but little doubt that these and all others 

 may be overcome by time and money." 



FRITH OF FORTH BRIDGE. 



Parliamentaiy sanction has been obtained for a bridge over the 

 Frith of Forth, of a magnitude which gives it great scientific inter- 

 est. It is to form part a of connecting link between the NortJi 

 Britis^h and Edinburgh and Glasgow Railways. Its total length 

 will be 11,755 feet, and it will be made up of the following spans, 

 commencing from the south shore : First, fourteen ojienings of 

 100 feet span, increasing in height from 65 to 77 feet above high- 

 water mark ; then six openings of 150 feet span, varying from 71 

 to 79 feet above high-water level ; and then six openings of 175 

 feet span, of which the height above high-water level varies from 

 76 to 83 feet. These are succeeded by fifteen oijeuings of 200 feet 

 span, and height increasing from 80 to 105 feet. Then come the 

 four great openings of 500 feet span, which are placed at a clear 

 height of 125 feet above high-water spi-ing tides. The height of 

 the in-idge then decreases, the large spans being followed bj^ two 

 openings of 200 feet, varying in height from 105 to 100 feet above 

 high water ; then four spans of 175 feet, decreasing from 102 to 

 96 feet in height ; then four openings of 150 feet span, varying in 

 height from 95 to 91 feet; and, lastly, seven openings of 100 feet 

 span. 97 to 92 feet in height. The piers occupy 1,005 feet in 

 aggregate width. The main girders are to be on the lattice 

 principle, built on shore, floated to their position, and raised by 

 hydraulic poAver. The total cost is estimated at £476,543. — 

 Engineering, Jan. 5, 1866. 



