Deep Waterways Commission, and the cost of this part of the work was paid jointly by that commission and this office. The principal features of it were measurements of flow and slope of parts of the St. Lawrence, Niagara, St. Clair, and Detroit rivers, including precise leveling operations through a distance of 126 miles on the St. Lawrence, from Cape Vincent at the outlet from Lake Ontario to St. Regis, and over a line 100 miles long from Gibraltar to Fort Gratiot, which provides for an accurate determination of the fall from Lake Huron to Lake Erie at all varying stages of water in these lakes, together with like determination of slope from point to point in the waterway connecting them. Some measurements of discharge were also made in the St. Marys River. Self-registering water gauges were established as fast as they could be supplied by the maker and 8 were in service at the close of the fiscal year, viz, 2 in Niagara River, 1 in Detroit River, 4 between foot of Lake Huron and Lake St. Clair, and 1 at Mackinaw City, Straits of Mackinac. Seven more remain to be placed to complete the series of fifteen as now contemplated. The reduction of data supplied by field operations has been carried forward as time and opportunity afforded, but it has not yet reached such a point as to justify publication at present. One unexpected feature of special interest and importance may be referred to briefly as a result of investigations so far made at the head of the St. Clair River, viz, a marked deepening since the survey of 1867 in that reach of the river which is one of the controlling factors in the outflow of Lake Huron. Steps are now being taken to make a most minute investigation of this locality and thereby obtain data that will be of vital importance in the study of the Lake-MichiganHuron level.

Details of operations outlined in the foregoing paragraph are contained in the subreport submitted herewith, being that prepared by Assistant Engineer E. E. Haskell, who was charged with their supervision and direction.

It has not been possible with the limited appropriations made during the last ten years to keep our lake survey charts up to the same standard of excellence that they possessed fifteen years ago; they do not correctly show the conditions now existing, and they are by no means so satisfactory to the navigator as they were fifteen years ago. Much more extended surveys and examinations than we have been able to make are necessary for developing natural and artificial changes that are constantly going on, in order that the charts may be brought up to date and kept so. But to do this at a reasonable rate of progress, it is absolutely essential that the annual appropriations of recent years be doubled for a few years to come, and for that reason the appropriation for this purpose should be at least $50,000 for the year ending June 30, 1901. This is certainly a small sum, considering the vast commercial interests dependent upon the accurate, up-to-date condition of these charts. But this work, important as we recognize it to be, must now be extended into a field of still greater importance for the time being, viz, the investigation of lake levels under the project inaugurated dur ing the last year, the immediate practical purpose of which is to devise the best means of regulating these levels, and of preserving or increas ing the navigable depth of natural and improved channels in the lakes and their connecting waters. Operations under this project are now dependent upon small allotments from two pertinent appropriations; but, if any reasonable progress is to be realized, it is essential that means be provided for continuing them on a much more extensive scale.

The work is so intimately connected with the lake surveys, past and present, as to induce the suggestion that its further prosecution be in connection with appropriations for these surveys. It will be absolutely impossible to make anything like satisfactory progress in these investigations unless an expenditure of at least $100,000 be provided for during the year ending June 30, 1901.

It is therefore recommended that the estimate for the year 1901 be made to include the two amounts specified in the foregoing paragraph, and that their appropriation be formulated as follows:

For survey of Northern and Northwestern Lakes, including all expenses of correcting, extending, and issuing charts, and investigating lake levels with a view to their regulation, to be available until expended........................

Money statement.

July 1, 1898, balance unexpended....

Amount allotted from act of March 2, 1895.
Amount allotted from act of July 1, 1898.
Amount allotted from act of March 3, 1899.

June 30, 1899, amount expended during fiscal year, including $36.90 paid by Treasury Department account Michigan Central Railroad Company.

July 1, 1899, balance unexpended..
July 1, 1899, outstanding liabilities.

July 1, 1899, balance available......

$150,000

$35, 699. 21 331.64

9, 739.50

18, 260.50

64, 030. 85

29, 429.86

34,600.99 2, 541.91

132, 059. 08

30,000

Dates and amounts of appropriations for survey of northern and northwestern lakes.

$15,000
20, 000

June 17, 1844.
March 3, 1845..

August 8, 1846..

Angust 12, 1818.

In addition to this balance reported by Lieutenant-Colonel Lydecker, there remains of this appropriation unexpended the sum of $6,882.21.

PRINTING AND ISSUE OF CHARTS FOR USE OF NAVIGATORS, AND ELECTROTYPING COPPERPLATES FOR CHART PRINTING.

UNITED STATES ENGINEER OFFICE, Detroit, Mich., July 15, 1899. COLONEL: I have the honor to make the following report of progress upon work pertaining to the investigation of lake levels, survey of northern and northwestern lakes, for the fiscal year ended June 30, 1899:

The project for this investigation of lake levels is given in your last annual report, beginning on page 3774 of the Report of the Chief of Engineers for 1898, and attention is invited thereto for a general statement of the work contemplated. Owing to the small appropriation available, plans for undertaking the work were limited to those features of the investigation considered most important, namely, the determination of the laws of flow from one lake to another and the causes and extent of fluctuations of lake levels from year to year.

The determination of the laws of flow from one lake to another required the establishment of a current-meter plant with which the discharge of the various connecting rivers could be measured and their discharge curves determined. A knowledge of the causes and extent of fluctuations of lake levels from year to year required an instrument for accurately recording what these changes are-a self-registering water gauge. The survey up to this time had not been engaged in any work where such an outfit was required, and so had neither a current-meter plant nor any selfregistering water gauges on hand. It was, therefore, necessary to provide this outfit, and during the previous fiscal year this work had been anticipated to the extent of considering and preparing plans for the current-meter plant and making working drawings for those parts that were to be constructed. The market offered no selfregistering water gauge adapted to the requirements of the lakes, so one had been designed.

The plans for the current-meter plant provided a catamaran for a working boat from which to use the current meters, and this was to be tended by a small tug suitably equipped for the work. A catamaran consists of two steel hulls, entirely inclosed, that are 27 feet long and of 5 feet beam. These hulls are joined by steel trusses carrying a platform or deck that is 16 by 17 feet in size. On this deck is placed an observing house about 10 feet square, which contains a suitable reel for hoisting and lowering the meters through a trapdoor in the deck and tables for recording instruments and keeping notes. The small tug required for tending a catamaran is provided with a steam capstan and the necessary appliances for the rapid and easy handling of anchors.

The contract for the construction of the catamarans, three in number, one each for the Niagara, St. Clair, and St. Marys rivers, was awarded to the Russel Wheel and Foundry Company, of Detroit, the lowest bidders, July 22. The first one of these was completed and delivered November 15, 1898, and the second and third March 8 and May 31, 1899, respectively.

The contract for the construction of the self-registering water gauges, fifteen in number, was awarded to Louis J. Wohnlich, instrument maker, of Detroit, the lowest bidder, July 22, 1898. The first instrument was delivered September 18, 1898, and the last one May 31, 1899.

The survey having no tugs of any kind made purchasing necessary, and the Fanny H., of Port Huron, was purchased October 12 and immediately fitted for service, but owing to the lateness of the season did not go into commission until the opening of navigation this spring. A second tug, the General G. K. Warren, was procured by transfer from the engineer office at Milwaukee, and arrived at Detroit May 20, since when she has been thoroughly repaired and fitted for service. The purchase of a third tug has not yet been made.

The current meters required, fifteen in number, were purchased from E. S. Ritchie & Sons, of Brookline, Mass. The order for them was given August 6, and three of them were delivered August 21, three more November 18, 1898, and the remainder May 7, 1899.

WORK ACCOMPLISHED.

Some of the data to be collected in an investigation of lake levels have a bearing on the problem of a deep waterway from the lakes to the sea. The United States Board of Engineers on Deep Waterways, having in charge the investigation of such a water route, has joined with the survey in collecting such information as was desired by both. Under this joint arrangement a line of precise levels was run from St. Regis, on the St. Lawrence River, to Cape Vincent, at the foot of Lake Ontario, a distance of 126 miles. These levels were run by Mr. David Molitor, assistant engineer, and connect a series of nineteen staff water gauges, distributed in the reach mentioned at critical points in the slope, for the purpose of determining the fall of the river. A series of gauge readings, taken at intervals of ten minutes, covering a period of ten days, was made on these gauges in the latter half of July. Permanent bench marks, at least one every 3 miles, were established and carefully described, so as to be of service in the case of future surveys.

A line of precise levels from Gibraltar, at the head of Lake Erie, to Fort Gratiot Lighthouse, at the foot of Lake Huron, was started, and the reaches from Gibraltar to Grosse Point and New Baltimore to Fort Gratiot covered by Mr. O. W. Ferguson, assistant engineer, between September 21 and December 15, 1898, a total distance of 73.5 miles. The reach between Grosse Point and New Baltimore, 27 miles, was run by Mr. David Molitor, assistant engineer, under the direction of this office, during June, thus completing the line. These levels connect a series of fifteen staff water gauges distributed at critical points in the slope along the St. Clair and Detroit rivers. Two series of readings, taken every ten minutes from 7 a. m. to 6 p. m., of six days each, have been taken on these gauges, the first in October, 1898, the second in June, 1899. A large number of permanent bench marks were established along this line for use in making future surveys.

A short series of discharge measurements of the St. Lawrence River at Ogdensburg were made by Mr. C. B. Stewart, assistant engineer, between October 6 and December 3, 1898. This series can be said to give only an approximation to the discharge for the stage of water prevailing at the time. The series should be greatly extended to reach a thorough knowledge of the laws of discharge of this important outlet. The work accomplished by this office, independently of the board of engineers, may be summarized as the discharge measurements of the Niagara River that have been in progress since September 1, the discharge measurements of the St. Clair River that have been in progress since November 1, with an interruption during the months of January, February, and March on account of interference from ice, and the discharge measurements of the St. Marys River that were prosecuted during the months of January, February, and March only, when work could be carried on upon the ice.

The work upon the Niagara River at Buffalo has been under the immediate charge of Mr. F. C. Shenehon, assistant engineer, and has consisted of making discharge measurements of the river from the International Bridge and collecting gauge readings from a series of gauges so placed as to give the level of Lake Erie and the slope of the river from the lake to a point some distance below the discharge section. The selection of the International Bridge section for this discharge work was governed by two facts: First, our equipment at the time was inadequate for open-river work, and second, this section had been used by the board of engineers on deep waterways in gaugings of the river made by them in the late fall of 1897 and the midsummer of 1898. This prior work made available a considerable amount of data relating to the section, and suggested more work to extend the range of the discharge curves.

During the ten months that this work has been in progress a large number of discharges, vertical and transverse curves, have been measured and a large number of ENG 99-242

gange readings collected. The reduction of these data has been prosecuted to a considerable extent, but not to the point where it is possible to give results for publication.

Mr. Shenehon has had in operation since the middle of January two of the new self-registering water gauges, one at the Buffalo Breakwater Light-House, to give a continuous registration of the level of Lake Erie, and the other at the foot of Austin street, in the river, which, with the one at the lake, furnishes a continuous record of the fall from the lake to the discharge section. These gauges have worked very satisfactorily, indeed, and are furnishing a most interesting record, establishing beyond question the importance of this method of collecting data relative to the stage of water in the lakes.

The work upon the St. Clair River at Port Huron and vicinity has been under the immediate charge of Mr. L. C. Sabin, assistant engineer, and has consisted of discharge measurements of the St. Clair River and the collection of data pertaining thereto. Mr. Sabin had charge of the collection of the two series of gauge readings made on the St. Clair and Detroit rivers.

For the limited time that this party has actually been engaged in field work a large amount of data have been collected and one very important discovery made. This discovery is that the head of the St. Clair, that narrow reach of the river extending from the lake downstream for about three-quarters of a mile-the reach that controls the outflow of Lake Huron-has materially deepened since the survey made in 1867. From the information so far collected the indications are that this deepening started about 1887 and continued with considerable speed until 1892. It may still be going on. The exact status of the matter can be told only when we have made an exhaustive study of past gange records of the lakes and have a very complete hydrographic survey of the locality to compare with the survey made in 1867. Such a survey is now in progress.

This deepening has unquestionably been a large factor in the lowering of the levels of Lakes Huron and Michigan, and it is significant that the mean level of these lakes has lowered 1.6 feet in the last ten years. During this period the mean lift at St. Marys Falls Canal has increased 1.5 feet, and the mean slope from the canal to Lake Huron has increased 0.1 of a foot.

One result of this discovery is to emphasize the importance of the investigation of lake levels that is now in progress and urge the necessity of more funds for carrying on the work of the lake survey. This work is now accumulating on account of insufficient means with which to do what is actually demanded.

Mr. Sabin has had in operation since February two of our new self-registering water gauges, one near the head of the St. Clair River, and the other about 3 miles below. He established a third gange last month at Roberts Landing on the St. Clair, and is now establishing a fourth one at the foot of Lake Huron. The record of these so far obtained is very satisfactory, and the gauge located at the head of the river, in addition to recording the stage of water, is collecting some most interesting information of seiches that occur in Lake Huron.

The work upon the St. Marys River has been under the immediate charge of Mr. Thomas Russell, assistant engineer. During the months of January, February, and March, while the river was frozen over, Mr. Russell carried on discharge measurements of the river by working through the ice. In addition to making a large number of measurements at Spry's dock section, where quite an extended series of observations were made during the winter of 1895-96, he made a number of measurements of the flow through the Little Rapids and the West Neebish channels. Mr. Russell has nearly completed the reduction of these observations.

Mr. Russell has also collected and reduced a considerable amount of rainfall data of the Great Lakes Basin, extending information that he had previously collected. Since May 20 Mr. Russell has been engaged in supplementing previous hydrographic work done in Potogannissing Bay. At the close of the fiscal year he had an about 180 miles of sounding lines.

A new self-registering water gauge was established at Mackinaw City, the Straits of Mackinac, May 12, and has been working very satisfactorily since. The remaining gauges of the series of 15 are being placed as rapidly as possible, and probably al will be in operation by the 1st of the coming September.

Considering the fact that at the beginning of the year the survey had no outfit with which to begin the investigation of lake levels, that it has all had to be constructed. I think it will be admitted that fair progress has been made.

Very respectfully, your obedient servant,

E. E. HASKELL, Assistant Engineer.

Lieut. Col. G. J. LYDECKER,

Corps of Engineers, U. S. A.