Litchfield enquirer., 1870-12-08

F sd shafts to depth Of l, ,500 feet in an Alpin. country, and after all leave an interval o
 more than six mifea, was not to be consid cred for a moment. The whole distanc (seven and 8 half milesl must therefore b. pierced from the two ends. A machin
 was eontrived by M. Maus, which, takin,
 advantage of the water abundautly availa ble on both sides of the mountain, was ex pected to reduce the time required for thu work to one fourth: but owing to the polit
 ical events of 1s48, this machine was nev
 CT actually put together and used. Afte
 the disturbed times had passed, and whel
 Italy became kingdom, the engineer
 charged with the execution of the worl
 had perfected the ingenious machiner,
 that has since been used for perforatinl
 the rocks Some time, of course, elapsed
 before operations could be carried on witl
 steadiness and yignT; but for many year.
 past the tunnelling has been going on, no
 only steadily but with gradually increasing certainty and facility. aud the work is now
 as we have already seen, almost in com
 plete state. M
 A visit to the tunnel works in thei
 present state is interesting and instructive aud is well worthy of the time and troubl, involved. 3< %tE B
 In front of, and at some little distance from the works, 2 hamlet has risen up fol
 the supply of such entertainment as mar and beast may require. in such place. The accommodations are not first rate, and the beds are better supplied with feas than the kitchen with meat. As may be supposed also, there is not much cholce in the way of food. but the traveller does not come te Pnn n1or k<~ I ger of starvutiUu. The buildings connect. ed with the works are on a scale propor. tionate to t5e magnitude of the work and the length of time it was certain to take. They include a capital house and offices for the resident engineer, another large house, including private apartments for for the principal employees. There are several other buildlugs affording excellent accommodation. The club is provided with billiard room and uews room, and is we'll supplied with every thing needful.
 Besides the dwelling-houses and offices. there are workshops of various kinds, and a very large shop supplied with numerous lathes and everything. required for con- structing and repairing all tue details of machinery used in the works. The perfo. rating machines are made and repaired here, and every thing needed in the way of metal woik, not involving extra dimen sions, is constructed on the spot. Imme- diately outside and also within this shop, one is struck by the odd appearance of gi- gantie blocks of stone riddled through and through with large holes. The stones are the hardest and toughest that could be found. The holes were bored with the steel chisels of the perforating machine. Entering the shop and looking around among the scores of machines at work, the visitor sees in one corner similar gigan- tic block of extremely hard quartz in which comparatively few perf0satiOns have been made. This block is ready for further ex- pertinent. The slender frame work of the iron supporting two instruments like small and working long mining chisel placed before it, is one of the machines used for boring, and intended to illustrate the process for the beneGt of visitors. can be comparatively more sim pie than this ingenious COZ trivance to per- forate the rock. The power made use of is air greatly condensed by set of large and powerful machines, worked by water power, and arranged in a series of four on the hillside, one below another The same Water, falling from one to another, works all the machines, and the condensed air, restrained for time in vast iron cylinders in each machine house, is distributed by long iron tubes to convenient spot with in the works, which it is conveyed to the perforating machines by elastic tubes, with out losing power by the distance to which it is conveyed. ~
 It is curious and instructive sight to see workman connect an elastic tube of about half an inch diameter with one of these machines and watch the result when a small tap is turned. A piston rod, work ing in an exceedingly small and short cyl finder, immediately flies backwards aud forwards with wonderful rapidity, regula- ted by small but rather heavy fly wheel Immediately ponderous ch.sei, six or seven feet long, and more than an inch in diameter, is set in motion, and having been previous placed in position strikes a succession of heavy blows against the stone. Fragments begin to fly in all di- rections. Each time that the chisel strikes it is withdrawn little way, very slightly turned, and immediately strikes agaln in the same hole. The stone experimented upon being of the hardest and toughest klnd, the effect is not seen for several strokes; but within two minutes, during which the writer watched the experiment, steel chisel was completely blunted and rendered useless, and there was Q hole made about two inches deep in the mass oi quartzite placed to operate upon. It is evident that nothing can resist such an at tack; and, indeed, holes are bored in this way in an hour that would formerly have taken day. The machines occupy very little space, and are by no means cum. brous. They can very easily be moved when and where they are needed. As ma
 ny as seventeen are at work together in the end of the tunnel where the advance is
 made. As the power is compressed air, they not only add no heat to the interior, but render it cooler by the absorption of heat during expansion. The air, when it escspes, is available for ventilation. I,
 would be quite impossible to carry steam at high pressure through pipes foul miles long, but little diminution of force is experienced in working with the air, al. though all the, engines and condensers, as
 well as the cylinders for storing the air, are outside the mouth of the tunnel. The length of pipe at present on the Pied.
 mont side is about four miles and quar
 ter, The pressure of air. commonly em. ployed is about six and a half atmospheres, or nearly hundred pounds on the square inch.
 The entrances of the tunnel at each end are not far from the hydraulic ma. chin os for o<n,,, ,,roco;ncr fha ais Thcco .r