THE USES OF ARTIFICIAL STONE. 315 



that purpose. Advancing engineering and chemical science, conjunctively ex- 

 perimenting on the varied properties of limes and cements, have succeeded in the 

 introduction of a cement possessing the valuable qualities of moderately quick 

 setting; and permanent induration. 



Vicat, Pasley and other practical investigators have ably assisted in this con- 

 sumation by their painstaking and laborious researches on limes and artificial 

 cements. Smeaton, however, in his experiments to ascertain the most suitable 

 mortar with which to construct the Eddystone Lighthouse, initiated the method 

 which eventually resulted in the discovery of Portland cement. Although lime 

 in combination with pozzuolana or other volcanic products had been, from the 

 time of Vitruvius, used to resist the injurious action of water, their beneficial con- 

 junction was not satisfactorily explained until the time of the Eddystone experi- 

 ments. Modern experience has somewhat modified Smeaton's conclusions, but, 

 nevertheless, we may consider ourselves much indebted to him for a knowledge 

 of hydraulic limes and the causes of their hydraulicity. 



Architects, profiting by engineering experience, now look upon concrete 

 with more favor, and begin also to appreciate its merits. Facility of executing 

 the most detailed ornamentation in Portland cement, mortar or concrete, will ul- 

 timately secure its general adoption. In Germany great attention is bestowed on 

 the preparation of a variety of articles in connection with building ; and machin- 

 ery of various kinds is used for molding and shaping architectural details which in 

 this country are performed by the expensive agency of the plasterer or stone 

 carver. Pipes for sanitary purposes are made by machine, and for many reasons 

 are most suitable for the conveyance of sewerage. Many miles of sewers under the 

 city of Paris have been constructed of betons agglomeres, a kind of concrete possess- 

 ing many valuable peculiarities. 



The several advantages secured in the construction of houses with concrete, 

 and the facility with which the materials of almost every locality may be adapted 

 for the purpose, is not the least important one. Improved means of resisting the 

 climatic influences of our changeable atmosphere are commanded by the use of 

 concrete walls, and numerous sanitary improvements are secured by its application. 

 Its progressive hardening properties enable it to resist effectually the damaging 

 influence of frost in the severest climates. Deleterious ingredients of the most 

 vitiated atmosphere fail to disintregrate or otherwise damage it. The compara- 

 tively non-absorbent character of Portland cement and the improvement which it 

 effects on any material with which it may be united, secure the maximum amount 

 of comfort to the inmates of a house so constructed. 



General Gilmore says : "Another interesting application of this material has 

 been made in the construction, completed or very nearly so, of the light-house at 

 Port Said, Egypt. It will be one hundred and eighty feet high, without joints, 

 and resting upon a monolithic block of beton, containing nearly four hundred 

 cubic yards. In design it is an exact copy of the Baleines light-house, executed 

 after the plans and under the orders of M. Leonce-Regnaud, engineer-in-chief. 



An entire Gothic church, with its foundations, walls and steeple, in a single 



