lock is pumped on to the scows and brought to the lock. It comes from the Lake Superior end of the work.

There is one more thing perhaps I will mention in connection with the lock; many of you are familiar with all these things, and some are not. This is a locomotive crane. It lifts 10 tons, reaches 40 feet, and its total weight, with its load, is 50 tons. It costs $4,000.00. One man operates it by five levers. One other man keeps up steam and cares for the two engines, and it works on a track 16 feet guage. This crane hoists, swings, turns and travels, and will do all at once. It will take a stone up, start off down the yard with it, swing about in the right position, and lay it on any pile.

The machinery consisted of two engines, both connected to do other service; also of a hoist, of shafts and gears for locomotion, also of shafts and gears for turning the crane. The gear frame is made of iron or steel beams. It interested me, to see it pick up a great stone as big as this table and walk off with it.

Now this new lock will cost about five millions of dollars. The dock is supposed to be 800 feet long and 100 feet wide when it is done, and even General Poe, who is in charge of all these improvements, seemed very much surprised when I happened to mention in his presence this fact with regard to the size of the lock pit. The pit is now open from end to end, and the masonry was going in last fall. The pit is about five or six hundred feet wide, and between fourteen and fifteen hundred feet long, and I happened to mention that the lock pit would contain a small sized village. The General said, "What's that?" I said, "Yes, sir, a good sized village, a street down through the middle, and good large sized lots and houses on each side." That is for handling the ships at the Soo.

The problem of the lock gates in that lock is one of the most serious that the engineers in this country have ever had to do with. The gate is to be 100 feet in two leaves. You all know how they shut together in the center. General Poe has considered the construction of these gates so important a matter that he has had engravings made of all the drawings, and copies of the plates made, to be deposited in different places, and copies of the drawings made and distributed in

widely separated localities in this country, so that they cannot by any possibility all be destroyed at once and the work have to be done all over.

And I come now to speak of the Hay lake channel, below the locks. Sorry I haven't a map, but this channel through Hay lake will bring the navigation chiefly in American waters, instead of on the boundary line of Canada and the United States. Where it now is, both sides have equal rights, and are disposed to be a little high handed in taking their rights, as near as I can discover.

This new channel will shorten the distance between the Soo and Port Detour eleven miles. They are making a twenty foot channel-through the rock they are cutting it twenty-one. The cost of the rock excavation, including blasting, etc., by dynamite, and depositing the rock in a dyke, for the purpose of marking the channel as if it were a canal, is $1.20 per cubic yard. The rock that does not have to be blasted is 57 cents per yard, and I wish to say for the credit of the profession, that this work is being done considerably below the estimates, and the price is running below the estimates more and more as it continues. They expected the work to cost three million dollars, and the expectation now is that it will cost less than two. In fact, less than one and three-quarters is the estimate I have heard. The earth is being moved at about 14 cents per cubic yard, out of that channel; in one case, 13 cents. That will be near enough for you to form an estimate.

That

The channel is to be 1,300 feet wide on the bottom. will give vessels room to pass. They have found it very desirable to manufacture the dynamite on the job. The first reason was that the percentage of nitro glycerine in the dynamite did not run even, and they couldn't depend on it, and the next difficulty was the transportation. High rates were charged. So they manufacture their own dynamite and make their own cartridges. It is the usual thing, let me say to those who are not familiar with such matters, for the drill scow, which may be represented by the table, to drill a row of holes along the front side of it, and as soon as drilled, there are 10 pounds of dynamite put into each hole and exploded right beneath one, within 20 feet. All you need to do is to raise yourself on

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your toes and you will escape all harm. The rocks will be shattered below, and be picked up by the dredge. I should like to talk to you about the machinery, but I shall not do it. Visit the works and you will find it of the deepest interest. This drill scow is one of the most perfect pieces of machinery of the kind.

In case any break occurs in any scow or tug boat, it is simply towed up to the machine shop (which is afloat) and fixed. If that isn't convenient, the machine shop is towed over to where the damage is done. This gives us an idea of the magnitude of the work. These men, three, four, five, perhaps, carrying on these stupendous works, costing about $7,000,000, are doing it as a matter of course, and yet there isn't one of us, nor the whole of us put together, that is able to form the slightest conception of what $1,000,000 is.

MR. APPLETON: I do think that now you are about it, and so ably describing those operations, you might elaborate a little more on the drill scow and on the dredges. You have spoken already of some parts of it; each of those drill scows are mechanical work shops, and I think you ought to say a little more, now that you are doing it so ably.

PROF. DAVIS: If it is the desire, gentlemen, I can describe the drill scow. The beauty of it is the economy and the simplicity of it. At the side of the scow is a vertical frame. There are horizontal tracks along the outside of that frame, to which are fastened the trucks, as you may call them, which carry the drills so they can be moved along lengthwise of the scow. These drills are three in number and can all be operated at once. The drills and their shanks of course are of sufficient length to drill the holes down to 21 feet in depth-in. fact a little more than that, making the drill shanks over 30 feet in length. There is a blacksmith shop on the scow, capable of keeping drills of such large size in order. On the scow, for the purpose of operating the drills, are large steam engines and boilers for handling different things about the scow, some of which I will mention presently, and for furnishing the steam for operating these rock drills. The scow

is anchored at its corners, and is kept in its place and arranged so that the bottom of the channel is completely and systemati

cally riddled with holes at the corners of five foot squares over all its surface.

I will say a word to the surveying portion of our convention. I like to talk to them. I will tell you how Mr. Ripley finds out, and he would tell you himself if he were not recovering from an attack of pneumonia, I will tell you how he finds out if the channel is the proper depth. He has a float 120 feet in length, with a hole in the middle of it, 100 feet long. Over the hole is a system of windlasses. From these chains are hung connecting to iron bars. By means of instruments, planted on the shore, he will locate that float at any place in the channel that he pleases. First, by means of his tug boat, or any other device, he will move the scow across the channel. The irons being suspended from the chains, sunk to a depth of 21 feet, will sweep the bottom of the channel completely, over 100 feet of its length. There are men standing with their hands on every chain, and the instant the bars touch bottom it is known. The scow is stopped, the sounding rod is set on that spot, the men on shore with instruments take a couple of sights to locate it, and they find that stone if it isn't a couple of inches in size. If any of you gentlemen see any way by which the contractor can escape his duty under these circumstances, Mr. Ripley would be glad to know it.

I was asked to say something about the dredges. I cannot say much to interest you. They put on dredges there that were too powerful at first and had to reduce the power to do the work economically, yet the present dredges astonish most of us. They will cut into solid sandstone rock, tear it to pieces. They bring it up in pieces up to two and three cubic yards. They found that the original dredges of the ordinary dipper pattern. were too powerful. They would not work economically. They were not being worked up to their capacity, so the power was reduced somewhat and they are doing the work and making money at the present day, as Mr. Ripley confidently informs Where they are drilling their work they receive $1.20 per yard, and where there is no drilling to be done, for 57 cents, and this place where they took out two or three cubic yards is where there is no drilling done.

me.

The dredges are, I think, made in Toledo; simply good,

plain, powerful machines, no nonsense, strict business.

There is a great fleet of tug boats, and all that sort of thing. It is seventeen miles to the Soo, and they have their private telegraph wire running down, and everything of that kind in shape, which shows of course the size of the job, and the strength of the men who are dealing with it.

There is one other thing I saw there that some of you may not have seen, and which you have seen accounts of in the papers, probably-what is called the "whale back." The whale back is cutting quite a figure in commerce. It is a very simply constructed plate metal vessel, having very little interior framework. They are simply built for carrying and storage capacity. They are all holds and hatchways, the quarters of the men taking up comparatively little space in the ends. They are built without bulwarks. The sea can wash completely over them. They are vessels of the largest class, as large as can be admitted to the locks at the present day-in depth, not in length. They are 250 feet long, or thereabouts, are made self-propelling and also as tow barges. They can carry freight for 2 mills per ton per mile. One of them crossed the Atlantic, you know, during the last summer, and I was surprised to be told that it was the first vessel that had crossed the Atlantic without a mast or sail. Possibly that is true. They are a singular looking vessel, but a great commercial success; cheap in the first cost, carrying capacity very great, and the repairs must be slight. Speed is very good, good enough for freight vessels, and they will undoubtedly revolutionize the carrying of bulk freight. It is not expected that they will make any great impression upon carrying package freight, at the present day.

Now that was what I saw when I wasn't fishing.

MR. TODD: I would like to ask if these whale backs are seaworthy?

PROF. DAVIS: I didn't talk with the captains of any of them myself, but I was told by Mr. Ripley, who did, that in one of the worst storms that he experienced, he walked from end to end in slippers, without getting his feet wet. They are long enough to span the space between three waves. one of the architectural problems in sea going vessels.

That was

If the