MECHANICS AND USEFUL ARTS. 37 



attached also by keys the cast iron shafts, which rising form the pile 

 heads, and uniting in a centre frame at the tops, form the supporting 

 braces for the basket frame, or distinctive mark of the Beacon, which 

 is secured to a prolongation of the centre pile at a height from the 

 level of the sand of 63 feet. The whole of the piles and shafts are 

 securely braced and counter-braced bv wrought iron tie-rods, keyed 



/ * ^j ^ 



to the sockets, rings or pile heads, forming altogether one of the most 

 efficient systems of frame work ever erected for such a purpose. The 

 whole weight of the structure is but 75 tons, and it cost the Govern- 

 ment but 810,000, whereas a stone structure would not cost less than 

 $35,000, that being the cost of a stone beacon on the same shoal, and 

 but 40 feet in height. 



GREAT TUNNEL IX HUNGARY. 



OXE of the longest, if not tlie longest tunnel in the world, is now in 

 a forward state of completion. It is situated in Hungary, and leads 

 from the shores of the river Gran, not far from Zarnowitz, to the 

 mines in the Schemnitzer hills ; it is two geographical, or about ten 

 English miles, long : it is intended to answer the double purpose of a 

 channel to drain off the water accumulating in the works, and of a 

 railway to transport the ore from the mines to the river. 



MODERN CYCLOPEAN WALL. 



A RECEXT number of the Allgemeine Zeitung contains an interesting 

 account of a visit which the writer had made to inspect the progress 

 of building a wall in the manner called Cyclopean, near Kiel, in 

 Schleswig-Holstein. He considers the effect of the work and the 

 style of execution far superior to any of the numerous remains called 

 bv the same name which he had seen in Italy, and sfoes so far as to 



v * C 1 



give it the preference over any other kind of wall, so far as the plain, 

 vertical surface of the material, apart from ornamental accessories, is 

 concerned. He thinks that the polygonal stones, exerting their pres- 

 sure in all directions, must insure stronger work than squared stones, 

 however closely iointed, which only act in the direction of oravitv. 



* ^^ 



Indeed, the innumerable many-sided and multangular stones of all 

 sizes seem run together into one compact mass, of which neither time 

 nor age will get the better. Neither mortar nor any other means of 

 binding the stones together is employed ; but the greatest care is taken 

 in fitting the granite blocks one into the other, the vacant spaces in 

 the wall as it is carried up being accurately taken off with a lead tape 

 forced with a hammer into all the angles of the openings, and then 

 applied to the flat hewn face of the block best suited, and next to be 

 brought to its proper shape by the workman. From the Avorkmen he 

 learned that the directions given them by the architect were, " Five- 

 sided and six-sided blocks, seldom four-sided ; straight lines, obtuse 

 angles, joint upon angle and angle upon joint ; all according to the 

 lead tape, and only inclined junctions." In tact, all the junctions be- 



