AMERICAN INSTITUTE. 587 



Trinity Church in New- York is built of New- Jersey sandstone, 

 which I fear will not prove a very valuable or lasting material, 

 from the fact that it absorbs about five-eighths per cent of rain 

 water, and parts with it readily. It is therefore natural to con- 

 clude that it will be liable to crumble from sudden expansion 

 or contraction. It is thought quite probable that the Washington 

 Monument will fall by its own weight, before it is completed, on 

 account of the inferiority of the stone composing its structure. 

 Specimens have been examined, 4 cubic inches of which sustained 

 a weight of 9,000 pounds, while 1 cubic inch of another specimen 

 sustained 18,000 pounds. The stones of which the Treasury 

 building and Patent Office are constructed at Washington, are 

 decaying and actually falling. Dr. Johnson says that those rocks 

 which amid decomposing influences, whether derived from cur- 

 rents of water, meteoric agencies, or vegetable growth and decay, 

 have been able to sustain themselves in high naked and angular 

 cliffs, unprotected by sojl, and yet unfurrowed by irregular dis- 

 integration, ai-e manifestly those to which the engineer and archi- 

 tect are to direct their attention, when they seek materials for 

 durable works of art. And after having found them, the next 

 step is to build a proper wall, impervious to heat and moisture. 

 A recent number of the Allgemeine Zeitung contains an inter- 

 esting account of the progress of building a wall called Cyclo- 

 pean, near Kiel, in Schleswig-Holstein, the execution of which is 

 far superior to any of the numerous remains called by the same 

 name in Italy, and it is considered superior to any other kind of 

 wall, so far as the plain, vertical surface of the material, apart 

 from ornamental accessories, is concerned. The stones are poly- 

 gonal, and exert their pressure in all directions, insuring stronger 

 work than squared stones, however closely jointed, which only 

 act in the direction of gravity. 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 building 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 workmen. Five- 

 sided and six-sided blocks; seldom four-sided are used; and they 

 are placed according to the tape in obtuse angles, joint upon angle 



