CONTINUOUS COMMUNICATION | With the Mainland,

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CAN IT BE ACCOMPLISHED ?

Hints from the St. Clair Tunnel

HOW IT WAS SUCCESSFULLY DONE.

Some

Illustrations. |

iwo princi} sl obje tions have been raiseu vrainst the proposed Tunnel or Subway rec ymmende t by Senator u »wian, as a

eans by which the Dominion Government : ment with Prince Ed this Province « he great boon of ‘** continuous communica- tion with the railway system of Mainland.” The first of these is, °° 1 ean, the

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not be done;” the second, ‘if it cost will be too great. We can now pvint to the St. Clair Tunnel! or Subway, which is now jaut a ] ssa proof, be yond the peradventure of a doubt, that it ean be done. Thistunnel has been made . ; =o through a strata of brick clay simuar to t hich ind the Strait of North- Loerian 1, at a cost iess han the estimate t j nul 1 mas i irs vere | : XI rit , li } 1! t ‘ é l wh ’ va nrecedeneu. : constructllo ’ s al sf & SUTPprisi ra | progress : un 3 prosecut ‘ npanied y ‘ : \ UAL s tha ' wr work fhe illustrations in LHE BXAMINER Co ia Ww nvey @ ciear 1cea r Ul meat by which this great work—the pattern of the greater W rk to be acc mpiis a unde 1e Strait of Northumberland—was accom- is} he chief instrument used is Know 4 Che Beach Seield. : ? fF ratty ’ } } y The mode srating borin ' ; ; : schine, w! 43 iously 1 luti sd tl I tunneling, 13 gray cally | rayed by the main illustrat sccompanying this descri} 1 The shield, which is operated sim!

} f } — e #) & seens taneously from each end of the tunneling consists of a strong cylinder somewhat re

; , . al , , . semmbling a huge barrel with both hea removed. The front end of the cylinder is sharpened, so as to have a cutting edge to enter the earth. The rear end of th evlinder, for a length of twofeet or so, 1 . } : ] ] +} 1 } made quite thin, and is called the hood. Arranged around the main walls of the

er and longitudinal therewith are a

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series OF Dy lrauli jacks, Ali Opera 1 from nena — 3 a a @common pump, each jack havin; ks ' ' a ee = —— . ‘ nema whereby it may be cut OL ifom tie imp

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whenever desired

Within, the shields are vertical and hori zontal braces and shelves. When at the iron plates or the masonry of which the | tunnel is composed are first built up within the thin hood of the shield; the hydraulic jacks are then made to press against end of the tunnel plates or masonry, which | has the effect to push the shield ahead into | the earth for a distance equal to the Jength | of the pistons of the jacks, say two feet, or not quite the length of the hood; and as the ' shield adyances men employed in the front of the shield dig out and carry earth through the shield. By the advance of the shield, the hood, within which the iron or masoary tunnel is built, is drawn partly off from and ahead of the constru

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the

back the

ed tunnel, thus leaving the hood cmpty. The pistons of the hydraulic jacks are then shoved back into their cylinders, and a new

section of tunnel is built up within the h 0 i as b fore described. Tk shield 3 then pushed, ahead and _ so n. The extreme end of the tunnel is! always within and covered and | protected by the hood. Inthis man-|

ner the earth is rapidly excavated or bored | out, and the tunnel built without disturb- ing the surface of the ground.

Each shield is circular, 21 feet 7 inches in diameter, 16 feet long, and is built of plate steel one inch thick. itis divided into twelve compartments by means of two hor- izontal and three vertical stays, which are built up to a thickness of to inches. These stays have a knife edge in front,

and extend back ten feet, leaving six feet of clear cylinder, into which the end of the tunnel extends.

Ten of the compartments ate permanently closed and braceingsof angleiron placed across them. The other two are provided with heavy iron doors, which can be closed at

once in case of accident or danger. These doors are situ ited at the bottom in the centre, and through them is passed all the

excavated matter. Flush with this head- ing (with their cylinders extending forward into the compartments) are twenty-four hydraulic rams at equal distances around the shield. These rams are eight inches in diameter, and have a stroke of twenty-four inches. :

The first illustration will give a popular understanding of the proportions of the different sections of this tunnel, of the dif- ficulties overcome in its completion, and of the magnitude of the work. From the American cutting to the river’s edge is 1,800 feet; from the Canadian cutting 1,950 feet; under the river 2,300 feet. The sub- terranean approaches are on the Canadian side 13,000 feet, on the Michigan side 9,000 feet. For the tunnel proper 2,196,400 feet of soil have been excavated. The cast iron lining has required 55,962,500 pounds. There have been used in securing this lining 859,242 bolts.

The walls of the tunnel are formed of thirteen cast-iron segments and a key.

These segments are cast with thirty-two holes in them, twelve in each side flange and four in each end. The inside diame- ter of the tunnel is twenty feet. The idea of substituting these segments for brick- work was suggested by Mr. Joseph Hobson, of Hamilton, Ont., the chief engineer of the St. Clair Tannel Company, and also chief engineer of the Great Western division of the Grand Trunk Railway. The tunnel will drain itself of the surface water entering by the approaches into an intercepting tunnel or vertical shaft 112

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feet in depth, extending to bed rock, which

is reached at that point. This well will be cleared by the highest pumping {engine of

The Great

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its kind in existence, which Henry R.

Worthington, of New York City, is erecting. It will be feet in height. will be on the bottom of the tunnel, while the cylinders will be on the level of the ground.

The lower third of the tube is being with brick and cement to prevent ceterior- ation of the casing by the brine that leaks from meat cars. One railway track will be

planked on both sides. The ties will be of iron, conforming in their curve to the

bottom of the tunnel.

Coke engines will be used for motive | power, in order to aveid as much as pos-! sible gas and smoke. An electric light station will be maintained on the Port Huron side, and the tunnel will bo at all tiraes as light as day.

As soon as the present tunnel isin run- | ning order another alongside of it will be’ begun, using the same machinery, with the exception of the shells of the pairof shields, which it was impossible to remove.

It is little more than one year since the tunnel proper was begun, the stec! shields having been lowered down inclines into the cuttings in August, 1889. Work on the cuttings, however, was begun in January, | 1889.

Freeing His Mind.

‘*T believe I'll sit down,” said Stanton, ‘and give that man a piece of my mind.”

** Do so,” said Lincoln ; ‘‘ write him now while you have it on your mind. Make it sharp ; cut him all up,”

Stanton did not need a second invitation. It was a bone-cruncher which he read to the President.

‘“‘That’s right,” said Abe; ‘‘that’s a good one.”

‘* Whom can I get to send it by 7?” mused the secretary.

‘*Send it?” replied Lincoln ; ‘*‘ send it? Why, don’t send it at all. Tear it up. You have freed your mind on the subject, and that is all that is necessary. You never want to send such letters ; I never do.”

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Tun thousand American Queen Cigars re- ceived to-day by Connolly & Co. ol] lw

now } over one hundred | The pump of the engine

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Railway Tunnel under the St. Clair River, between t

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THURSDAY, OCTOBER 16 1890_

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A, pump shaft. B, brick air shaft, C, cuttings, DD, bulkheads. Fig. 2.—Cross section

Fig. 1.—Sectional elevation and. plan of tunnel ;

of tunnel and river. Fig. 3.—Map showing location Fig. 4.—Plan of Pt. Huron and Sarnia, showing position of tunnel.

j Fig. 5.—Section‘and plan of iron shoe of shaft, Fig. §,—Segment_of cast iron of which the tunnel is composed,

A Paste That Will Stick Anything.

| A paste which will stick anything is said | by Prof. Winchell to be made as follows : Take two ounces of clear gum arabic, one and a half ounces ot fine starch, and half .an ounce of white sugar. Dissolve the gum arabic in as much water as the laun- dress would use fur the quantity of starch indicated. Mix the starch and sugar with the mucilage. Then cook the mixture in 6 vessel suspended in boiling water until the starch becomes clear. The cement should be as thick as tar, and kept so. It can be bept from spoiling by the addition of cam- phor or a little oi] of cloves.

} } xs a . . . + * . . oven a, at 2 lie ehield, showing hood and 1ams. Fig. 2.—The shield in place on grade. Fig. 3 —interior view of shield and tunnel, Fig. 4.—brony view o1 suacia Fig. 5.—Lowering ef the shield to the heading 1. © = B B ‘ Ye a Hn ‘ re = - Diy Sanaernee ‘ e 5

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To cure a felon, says a correspondent, mix equal parts of strong ammonia and water, and hold your finger in it for fifteen minutes. After that withdraw it and tie s piece of cloth completely saturated with the mixture around the felon and keep it s there till dry.

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| SPA YEARS IN USE, “uw PRICE 25°PER BOTTL

ARMSTRONG & CO CSP eae ei,