1869.] Experimerdal Besearches on the Froiierties of Steel, 21 



Another large deposit of sulphur, about two miles distant, occurs 

 in what is known as Chalk Mountain, so called on account of its 

 peculiar white appearance, caused by the decomposition of the 

 volcanic rock ; and still another at Sulphur Springs, farther east on 

 the road to Colusa : but in neither of these localities is the sulphur 

 discoloured by the presence of cinnabar. The rocks at Chalk 

 Mountain are extensively fissured and much decomposed by the 

 action of steam and acid vapours, and springs yielding water highly 

 charged with carbonic acid are numerous throughout the district. 

 In fact, volcanic materials and hot sj)rings occur in a line from 

 Clear Lake eastward toward the Sacramento valley, and, as Pro- 

 fessor Whitney remarks, there is evidence of a transverse fissure 

 extending from the Geysers across the volcanic belt, of which 

 Mount St. Helena is the culminating point, to the Sacramento 

 Talley. 



III. EXPEKIMENTAL KESEAECHES ON THE MECHA- 

 NICAL PKOPEETIES OF STEEL. 



By Wm. Fairbaien, LL.D., F.K.S., &c. 



The present may be justly considered the age of iron, as in every 

 branch of industry where force, form, and motion are required, 

 iron enters largely into construction, and its powers of application 

 have supjDlanted almost every other material. It presents wonderful 

 facilities in its adaptation to every description of art, whether of the 

 useful or decorative style; and its improved tenacity, elasticity, and 

 ductility have enlarged its field of usefulness in the construction of 

 buildings, ships, steam-engines, bridges, and machinery of all sorts 

 where strength combined with lightness is required. To this 

 powerful and valuable material we are indebted for railways, loco- 

 motives, and roUing stock ; and there is no branch of manufacture 

 in which it does not form a whole or a prominent part. Possessed 

 of such a material in its cheapest and best forms, we should be de- 

 ficient in duty if we left it in the rude state in which it was found 

 in the days of Cort, and his immediate successors. That great 

 improvements have been effected of late years does not admit of 

 doubt, and there is probably no material that has undergone greater 

 changes in its manufacture than ii'on ; and judging fi'om the attempts 

 that are now making, and have been made, to improve its quality 

 and to enlarge its sphere of application, we may reasonably conclude 

 that it is destined to attain still greater advances in its chemical and 

 mechanical properties. The earliest improvements in the process 

 of the manufacture of iron may be attributed to Cort, who intro- 



