the work can be done for forty-five and one-half cents per cubic yard, and probably in one season.

4. That with three Osgood machines, nine scows and one tug purchased, the work can be done for fifty cents per cubic yard, and in a part of

one season.

5. That with one Boschke machine and eight scows purchased, and one steam-tug, (whether hired or purchased,) the work can be done in a part of a season at thirty cents per cubic yard, if the advantages and capacity of the machine be as great as above stated.

6. That with one double dipper machine, (Morris and Cummings patent,) six scows and one tug purchased, the work can be done for thirty cents per cubic yard, and in one season, if the advantages and capacity of the machine be as great as above stated.

These estimates are all based on the supposition that the machines, scows, and tugs will be sold on the close of this single work, in which event it would be advisable to employ either the Boschke or the double dipper machine, or else to purchase and employ two Osgood machines, with requisite scows and tug. But should it be deemed advisable to retain the machines, scows and tug, for other public works, in this department or elsewhere, the comparative cost of the work per cubic yard, will be as follows, viz:

1. With two Osgood machines, six scows and one tug, purchased and kept in order, at twenty-five cents per cubic yard, or $20,000 for the whole work.

2. With one Boschke machine, eight scows and one tug, purchased and kept in order, at ten cents per cubic yard, or $8,000 for the whole work.

3. With one double dipper machine, (Morris and Cummings patent,) six scows and one tug, purchased and kept in order, at fifteen cents per cubic yard, or $12,000 for the whole work.

The foregoing estimates for the Osgood machine are, in my opinion, reliable; but those for the Boschke machine, and for the Morris and Cummings patent, are based on the best information I have in regard to their capacity for work. Before recommending the adoption of either of these machines, I would desire to see them in operation in Boston, New York, and Buffalo, and be fully satisfied as to their respective advantages over the Osgood and other machines.

For the purpose of comparing the foregoing estimates for cost of work with the bids made for the work to be done by contract, I will add the following:

1. Lowest bid received from A. B. Cooley and Co., thirty-four cents per cubic yard.

2. Next lowest bid received from I. F. Hayden, of Buffalo, New York, for doing the work with a double dipper machine, at forty-four cents per cubic yard, or $35,200 for the whole work.

3. Lowest bid received from A. R. Wright, of Portland, Maine, on inviting proposals a second time, at sixty-five cents per cubic yard, or $52,000 for the whole work.

Mr. Hayden's price for doing the work is a reasonable one for a contract, and I think that he would still be willing to enter into a contract on those terms, if allowed to have one season for its execution. I would, however, recommend, in conclusion, that suitable machines, with requisite scows and tug, be provided by the United States, so that the dredging may be completed this season, without fail, and that the machinery be retained by the department for use in other engineering operations. This, in my opinion, is the o way in which the government can be

assured of the satisfactory execution of such work, either in the time or cost of its execution.

Very respectfully, your obedient servant,

GEO. THOM,

Lieut. Col. of Engineers, Bvt. Brig. Gen. U. S. A.

Maj. Gen. A. A. HUMPHREYS,

Chief of Engineers United States Army,

Headquarters Corps of Engineers, Washington, D. C.

U 2.

UNITED STATES ENGINEER OFFICE,

Portland, Maine, March 15, 1869.

GENERAL: I have the honor to report that, in compliance with your instructions, I have visited New York and Boston, for the purpose of examining into the merits of the dredging machine known as Morris & Cummings's patent, in operation in New York Harbor, and Boschke's patent, in Boston Harbor, with a view to ascertaining the most suitable and desirable machine for dredging in this harbor. The double-dipper machine (Morris & Cummings's patent) operates with very great facility and rapidity, and to any desired depth; the only question in my mind being as to the hardness and tenacity of the material which it is capable of excavating, as its power of penetration seems to depend, in a great measure, upon the weight of the dipper. The material which I saw it excavate in New York Harbor was a stiff though not very tenacious mixture of mud and clay, which nearly filled the dippers (of 1 yard capacity) at the rate of about three times in every two minutes, at a depth of fifteen to twenty feet. An examination of the books of Messrs. Morris & Cummings, which I was kindly permitted to make, showed that the machine (with dippers of 1 yard capacity) is capable of excavating, under favorable circumstances, fifteen hundred cubic yards per day; and generally it excavates about seven hundred to nine hundred cubic yards per day.

Messrs. Morris & Cummings claim for their machine that it can excavate stiff clay, or any other material as tenacious, as can be excavated with other machines, and so do others who have used these machines. Others, again, whose opinions are worthy of consideration, assert that these machines cannot work in stiff clay, or to advantage in any material into which the dippers will not penetrate by their own weight. My opinion is that they will work to better advantage in this harbor than any other machine, except, perhaps, Boschke's, or, possibly, Taggert's: first, because the material is not too stiff or tenacious for it; and, second, because it can operate with facility to any desired depth and with less danger of breakage and interruption by ocean swells, than other machines now in use. I will also here state that for removing slabs, edgings, and boulders, such as obstruct the Penobscot, Union, and St. Croix Rivers, in this State, for which appropriations have been made or asked for, there is no other machine (unless it may be Taggert's) which can accomplish the work so effectually, in my opinion, as Morris & Cummings's machine, with its skeleton dippers, which are especially designed for such work. In my report of January 6, I underesti mated the cost of these machines. Morris & Cummings offer to make all the machinery complete for one machine, with latest improvements,

for the sum of $10,000; the hull, made here, would cost about $7,000, making the entire machine cost $17,000, or $3,000 more than my previous estimate. Messrs. Morris & Cummings will also require the United States to pay $10,000 for the privilege of using the patent in this State. This appears to be a large sum; but, on inquiry, is not more than is paid by private parties for its use elsewhere.

In Boston Harbor I also examined the working of Boschke's machine and was very favorably impressed with it. This machine consists of a large iron concave plow, which excavates the material, and buckets, on an endless chain, which empty the plow and carry off the material thus excavated. The machine built by Mr. Boschke for Boston Harbor is a double one with two plows and two sets of buckets or elevators, but the experiments made by him with it during the past winter satisfy him that for ordinary purposes a single elevator would be better.

This machine has a threefold advantage over most others: first, in the depth to which it can excavate without loss of power; second, in the very hard, stiff, and tenacious material which it can excavate; and, third, in the quantity of work it can do. I examined some of the material being excavated by it at a depth of thirty feet and found it to be a very stiff, compact clay. As to the quantity of work which it can do per day, I am not yet satisfied, nor do I think that Mr. Boschke is, as thus far he has been experimenting and improving on it. But for a single elevator he claims its capacity at not less than twenty-five hundred cubic yards per day, if I mistake not. I should not, however, estimate its average day's work at more than one thousand cubic yards.

At my request Mr. Boschke has furnished estimates and propositions for his machine, (a copy of which is furnished herewith,) from which it appears that for all the machinery and iron work complete for one single machine he will charge $20,000. The hull built here would cost about $8,000 making the machine, complete, cost $28,000, or $1,000 more than my estimate of January 6. For the privilege of using his patent in this State, Mr. Boschke asks the sum of $5,000.

In conclusion, I have to respectfully recommend that for removing the slabs, edgings, and boulders which obstruct the navigation of most of the rivers in this State, the Morris & Cummings machine, with skeleton dipper, should be used, and that the same machine, with dipper of 1 cubic yard, be used for dredging in this harbor.

But

I do not feel fully satisfied at present as to Mr. Boschke's machine, although, after further experiments and proposed improvements, it may turn out to be the best machine for work in this and other harbors. for removing slabs, edgings, and boulders, I know of none to compare with the Morris & Cummings patent.

Should it be decided to contract for the dredging in this harbor, it will not cost more than fifty-five cents per cubic yard, (a proposition made by Messrs. J. T. Hayden & Co., of Buffalo, New York,) or, say $50,000 for the whole work. But, in my opinion, the government can do this work at a cost not exceeding twenty-five cents per cubic yard, by building and operating its own machinery.

Taggert's machine, to which I have above referred, is a double-dipper machine, in which the dippers are opened and closed by handles, like a pair of scissors. It would appear to have some advantages over the Morris & Cummings patent in excavating hard material, if the leverage of the handles can be made sufficiently strong. But it has not been enough in use to prove these advantages.

The foregoing report would have been made earlier had I not been

prevented by sickness, with confinement to my bed and home for more than two weeks past.

I am, very respectfully, your obedient servant,

GEO. THOM,

Lieut. Col. of Engineers, Bvt. Brig. Gen. U. S. A.

Maj. Gen. A. A. HUMPHREYS,

Chief of Engineers United States Army,

Headquarters Corps of Engineers, Washington, D. C.

BOSTON, February 24, 1869.

SIR: I have received estimates for building all machinery, elevators, and buckets for one of my patent dredges with one elevator.

I could furnish a double fourteen-inch cylinder engine with boiler and smoke-stack, donkey engine, two eight-inch cylinder engines and gears for hoisting elevator, the elevator with buckets, chain, all the shafting and gears to dive the buckets, elevator, hauling chain, hand-hoisting, &c., in fact, all the machinery and iron work required to set up in working order a complete machine for 'dredging, except the hull or vessel for the dredge, all this work warranted to be of the best material and workmanship, for the sum of twenty thousand dollars, and the use of the patent for the United States government for the State of Maine for the sum of five thousand dollars. Or the government may build the machine at their own expense, and pay the five thousand dollars for the use of the patent for said State.

I am ready to enter into any contract you may see fit to make, to purchase the machine and scows you may build under my patent right at the expiration of a reasonable time, for a sum we may agree upon, as I am going to build myself, in the course of a few years, several of the single elevator machines for work laid out in Boston Harbor.

Most respectfully,

Gen. GEO. THOM, U. S. A.,

A. BOSCHKE.

Portland, Maine.

APPENDIX V.

SAN FRANCISCO, CAL., July 31, 1869.

GENERAL: I have the honor to submit the following report of my official operations during the fiscal year ending June 30, 1869:

The operations have been conducted under the following appropriations:

Surveys of military defenses.

Purchase and repairs of instruments.

Removing obstructions in Willamette River.

Surveys and examinations on Pacific Coast.

Repair, preservation, extension, and completion of certain public works of river and harbor improvements.

River and harbor improvements for the year ending June 30, 1869, and for the year ending June 30, 1870.

The amount of the two last-mentioned appropriations, though having different names, are applied to the same improvements. In addition, I

am the engineer of the twelfth and thirteenth light-house districts and a member of the board of engineers for the Pacific Coast.

The operations under the above-named appropriations will be described in the order named.

SURVEY OF MILITARY DEFENSES.

Instructions having been received from the Chief of Engineers to cease disbursements under this appropriation, and to deposit the amount on hand to its credit with the assistant treasurer at this place, the amount on hand was so deposited and the account closed. The previous expenditures had been principally for collecting meteorological data, and a considerable amount had been collected which had not been reduced.

Upon representations made by me to the Chief of Engineers of the importance of the work being completed, I was given a small amount for that purpose. Nearly all the observers, however, agree to continue the observations, except those taken hourly, without compensation, and the work has continued with the expense of only about $150 per month. The results are valuable and increase in value as the series of observations become longer.

The following are the amounts received and expended during the fiscal year ending June 30, 1869:

By the direction of the Chief of Engineers the amount on hand from this appropriation at the end of the first quarter of 1869 was deposited by me to its credit with the assistant treasurer at San Francisco, California, and the accounts under it thus closed.

The following are the amounts received and expended under it:

This work has been under the immediate charge of my assistant, Lieutenant W. H. Heuer, United States Engineers.

The operations on this river during the past fiscal year have been