BUILDING AND ORNAMENTAL STONES. 627 



Calcareous sandstone. Gray ; compact. From quarries at Lapa, District of Leiria, 

 Estremadiira Province. American Institute of Mining Engineers, 188G. 37897. 



Mica granite. Fine ; redilish. From quarries at Gramacos, Oliveira do Hospital, Dis- 

 trict of Coimbra, Beira Province. Portuguese Centennial Commission, 1876. 27818. 



Coarse ; gray. From quarries at Santa Ovaia, Oliveira do Hospital, District of 



Coimbra, Beira Province. Portuguese Centennial Commission, 1876. 27819. 



Gray; coarse; porphyritic. From quarries at Pedreirada S6, Taboa, District of 



Coimbra, Beira Province. Portuguese Centennial Commission, 1876. 27820. 



Fine ; light gray. Portuguese Centennial Commission, 1876. 27775. 



Slate, Coarse blue-gray. From quarries at Espariz, Taboa, District of Coimbra, 



Beira Province. Portuguese Centennial Commission, 1876. 27756. 

 Granite. Coarse; gray. 5 by 5 by 1 inches. Cintra, Estremadura Province. Amer- 

 ican Institute of Mining Engineers, 1886. 37893. 

 Marble. Pink ; fine and compact. Lisbon. Portuguese Centennial Commission, 



1876. 26450. 

 Dolomite r marble]. White; crystalline. 5 by 5 by 1 inches. Terra do Tanque. Es- 

 tremadura Province. 37891. 



White; crystalline. 4 by 5 by f inches. Locality, etc., same as last. 37892. 



Limestone (stalagmatic). Brown mottled; irregular oval mass, about 17 by 8 by 



4 inches. Rock of Gibraltar. Centennial Commission, 1876. 25027. 

 Stalagmite [marble]. Brown. Small slab, 3 by 4 inches. Rock of Gibraltar. A. 



R. Crittenden, 1886. 38444. 

 Hornblende andesite (?). Fine dark gray, nearly black, with small white spots. 



This stone is used in hewn and rubble work in localities where there is no other. 



It is very easy to cut in blocks of any size. 5-inch cube. From quarries near 



Ponta Delgada, on the Island of Sho Miguel, Azores. Portuguese Centennial 



Commission, 1876. 37904. 

 Basalt. Coarsely vesicular; dark gray, almost black in color. Used for hewn stone 



of inferior quality to remain in sight inbuildingsofasuperior construction. Also 



used aa an imitation of hewn stone when covered with cement, which adheres 



very well to the asperities of the stone, and as hewn and rubble stones in inferior 



constructions. Locality, etc., as above. 37905. 



Dark gray; fine and compact; somewhat vesicular. This stone is very hard 



and difficult to hew, and on this account is used only for rubble work and as 

 loose stone in breakwaters. Locality, etc., as above. 37906. 



Dark gray, nearly black; very vesicular. Used as a second-rate stone in the 



commonest kind of hewn work. Locality, etc., as above. 37907. 



Fine and compact; dark gray. A first-class stone,used in hewn work in build- 



ings of superior construction. Locality, etc., as above. 37908. 



Red; ferruginous; coarsely vesicular. Santa Cruz de Tenerifl'e, Canary Islands. 



Portuguese Centennial Commission, 1876. 27712. 

 Pozzuolana. Volcanic clay; employed with great success to give, when mixed with 

 liuio not hydraulic or slightly hydraulic, the properties which the latter requires 

 for composing hydraulic mortars. Very abundant in St. Michaels,and explored 

 in great scale in the suburbs of Ponta Delgada for the buildings of the locality 

 and for exportation to tho eontinent of Portugal. It is generally employed in 

 all the public works of the country. In constructions out of water, or in hy- 

 draulic works by tides or in fresh water, the masonry is made with mortar com- 

 posed of one part oflime and three parts of pozzuolana, using lime not hydraulic 

 for tho iirst kind of works and slightly hydraulic for the second. For works 

 constantly exposed to the sea slightly hydraulic lime, pozzuolana, and coarse 

 sand are mixed together in equal parts. (Portuguese Centennial Catalogue, 

 p. 95). Locality, etc., as above. 35527, 



