This Book is in Good Condition. Clean Copy With Light Amount of Wear. 100% Guaranteed. Codice inventario libreria
Riassunto: This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1885 Excerpt: ... and cylinder, also the surrounding clay and the bulkhead above, were in motion, settling slowly. By the time the shaft had been firmly founded on the rock the pile bulkhead had settled nearly five feet. After the shafts had been sunk and secured the excavation for the tunnel proper encountered no serious obstacles. The work was carried on at six different headings. From the middle and east shafts work progressed in both directions, and from the west shaft and the upper end of the incline at Squantum single headings were driven. The incline descends one foot vertical in six feet horizontal. At this point a heading was driven downwards for about 400 feet and then stopped, owing to the difficulty and expense of removing the water which accumulated at its face. At the middle shaft power drills, driven by compressed air, were used, and at other points hand drilling was employed. There was not much difference as to either expense or rapidity in the two methods. By either an advance of four feet was considered a fair day's work. The chief merit of the air drills seemed to be that they were not demoralized by pay-days, and never struck for higher wages. Various forms of nitro-glycerine were employed as explosives, and no casuality occurred through its use. The average diameter of the excavation (Plate XXI., Fig. 2) was about 10.2 feet, approximating very well to the 9.5 feet required to receive the final brick lining. The excavated material, amounting to about 25,000 yards in all, was deposited around the shafts, forming small islands. The maximum amount of water leaking into the tunnel at any time was 64,000 gallons an hour. The headings between the east and middle shafts met Jan. 24, 1882, and those between the middle and west shafts met June 22, 1882. Lining th...
Condizione libro: Used
AbeBooks è una piattaforma online di libri nuovi, antichi, usati e fuori catalogo attiva dal 1996. Ti mettiamo in contatto con migliaia di librerie di fiducia sparse in tutto il mondo, che offrono milioni di libri. L'acquisto sui nostri siti è semplice e sicuro al 100% - cerca il tuo libro, comprane una copia attraverso il processo di acquisto protetto e la libreria ti invierà il libro direttamente.
Opere antiche e rare, prime edizioni, i libri più costosi venduti su AbeBooks e altri contenuti dedicati ai bibliofili d'eccezione.
Acquista subito i libri di seconda mano. Tutte le opere che avresti sempre voluto leggere a tua disposizione a un prezzo speciale!
Libri nuovi, usati, italiani e stranieri che stavi cercando, in spedizione gratuita e senza spesa minima!