WELL KNOWN BUILDING MATERIALS 
215 
Mg O, 
K, O. 
Na, O 
O. 
0.80 
0.21 
0.45 
0.45 
Total 100.05 
Manganese, titanium, and carbon dioxide were absent. 
III. THE HARD JEWISH. 
In the Proceedings of the Iowa Academy of Science for 1913, 
page 193, we described a rock from Solomon’s quarries, Jeru- 
salem, known as the ‘‘Royal”. Mr. Herbert E. Clark of Joffa 
Gate, Jerusalem, kindly sent us another variety from another 
portion of the same quarries, known as “Hard Jewish’'. It is 
of a buff color, hard, brittle, fine-grained, compact, and to all 
appearances a very durable limestone. The specific gravity of 
2.7, and also the fact of its breaking with a conchoidal fracture 
indicate its fineness of texture and compactness. It seems much 
harder than the “Royal”, before mentioned and in color there 
is a marked contrast to the snowy Avhiteness of the “Royal”. 
The analysis resulted as follows : 
Per cent. 
Ca CO.... 87.84 
Mg C 63 7.10 
Si O 2 3.51 
Fea O 3 0.32 
AI 2 O 3 l.O'S 
Total 99.85 
We desire to record our thanks to Miss Bonnybel Artis, 
Ellery Botts, and John A. Cogswell for assisting in the analy- 
ses. 
America doubtless has as fine and durable building stones as 
may be found in any quarter of the globe, but the high cost 
of labor has prohibited their widest use. As timber has greatly 
advanced in price in recent years, building stones may be des- 
tined to be more extensively used. 
Chemical Laboratory, 
Cornell College. 
