. Bulletin - United States National Museum. Science. -. V • Figure 14 YVksi portai 01 11 1 i* k. {Photo courtesy of State Library • \i husetts.) .1 degree of effectiveness impossible with the powder train and cord fusing used with the black powder. \ the the period of experimentation was over. The tunnel was being advanced by totally modern methods, and to the present day the overall concepts have fundamentally unaltered: the Bur- leigh piston drill has been replaced by the lighter hammer drill; the Doane drill carriage by the more flexible "jumbo"; nitroglycerine b
. Bulletin - United States National Museum. Science. -. V • Figure 14 YVksi portai 01 11 1 i* k. {Photo courtesy of State Library • \i husetts.) .1 degree of effectiveness impossible with the powder train and cord fusing used with the black powder. \ the the period of experimentation was over. The tunnel was being advanced by totally modern methods, and to the present day the overall concepts have fundamentally unaltered: the Bur- leigh piston drill has been replaced by the lighter hammer drill; the Doane drill carriage by the more flexible "jumbo"; nitroglycerine by its more stable descendant dynamite and its alternatives; and static- electric blasting machines by more dependable magnetoelectric. But these are all in the nature of improvements, not innovations. Unlike the preceding model, there was Liood docu- mentation for this one. Also, the Hoosa< was appar- .iit 1 \ the firsl American tunnel to be well recorded photographically. Earl) flashlight views exist of the drills working at the heading Mi'-;. 6) as well as of the portals, the winding and pumping works at the cen- tral shaft, and much of the machinery and associated aspei ts 0! the projei t. I hese and copies ol drawings of much of Doane's experimental apparatus, a rare technological record, are preserved at the Massachu- setts state Library. Soft-Ground Tunneling v,, great is the difference between hard-rock and soft-ground tunneling that the) constitute two almost separate brain lies ol the held. In penetrating ground lacking the firmness or cohesion to support itsell above an •_', the n iner's . hiel concern is not that ol it 11 o\ ing the n at >> \\ ,. first published in Basel in 1556. During its time of active influence, which extended for two centuries, it served as the authoritative work on the subject. It remains today an unparalli led earl) record of an entire branch of technology. I he superb woodcuts of mine workings and tools in themselves co
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
