67 
HALL 68. 
BUILDING STONES. 
This Hall contains a systematic collection of building stones. 
Case 1. — Artificial stones for building. These are moulded 
like terra cotta. 
Case 2. — Limestones and marbles. Four-inoh cubes of many 
of the limestones and marbles of the United States used for build- 
ing. A few English and Spanish limestones are included. 
Case 3. — Sandstones. Four-inch cubes of many of the sand- 
stones of the United States used for building purposes. 
Case 4, — Marbles and granites. Four inch cubes of many 
of the marbles and granites of the United States used for building 
purposes. These four kinds of rock constitute nearly all the val- 
uable building stones used in temperate climates. 
Case 5. — Building stones of Mexico and Ecuador. These 
are mostly volcanic rocks, lavas and tuffs, which are sufficiently 
durable, for mild climates and yet soft enough to be easily worked 
with simple tools. The building stones from Ecuador are the 
ordinary pumice-stone. 
Case 6 . — Cubes of granite, showing the various ways in 
which the rock may be dressed. 
Platform 7. — Slate, Wales. These specimens illustrate the 
manner in which blocks of slate are split or cleaved into a series 
of laminae or thin plates, which may be afterwards cut to uniform 
sizes and used for roofing. 
See also Hall 65, Case 4A. 
