2. WILLETS POINT, NEW YORK HARBOR, April 22, 1891. COLONEL: I have the honor to submit herewith the results of tests ordered made on the Portland cement being used in the construction of the museum. A mistake was made at first owing to the fact that two kinds of cement are being used and the workman obtained the wrong kind. This led to the decidedly unfavorable verbal report I made to you April 6, 1891, and an apology is due the company making the Portland cement for the report made to them on its condition. Incidentally, this mistake was valuable as showing that the Rosendale cement being used is destitute of hydraulic properties, although possessing considerable strength when dried and set in air. The tests of the Portland cement were made under the same conditions as the cement tests I made last year, a description of which is contained in my report of June 5, 1890. The mean of 9 specimens made of one part cement and two parts sand gives 166.6 pounds breaking strength per square inch.* Some briquettes of pure cement were tested and broke very uniformly at about 500 pounds, or a stress of 222.2 pounds per square inch of cross-section. The behavior of the cement with sand is very creditable; but I am somewhat surprised to find that the pure cement does not give a higher tensile strength as compared to the sand briquettes. Very respectfully, your obedient servant, Lieut. Col. W. R. KING, Corps of Engineers. A. M. D'ARMIT, Second Lieutenant of Engineers. 3. WILLETS POINT, NEW YORK HARBOR, June 22, 1891. COLONEL: I have the honor to report that in compliance with your verbal instructions I have made the additional tests requested by the Keystone Cement Company. The cement was taken from the box sent by them for this particular purpose. The briquettes were very carefully made and were exceptionally fine specimens. They were set 1 day in air and 7 [67] in water. On testing, however, they failed to justify the claims of the Keystone Company, the maximum strain borne by the neat briquettes being 525 pounds, or 233 pounds per square inch, the average being about the same as found at the previous trial.+ 4. WILLETS POINT, NEW YORK HARBOR, July 15, 1891. COLONEL: I have the honor to submit herewith the result of the tests made of the Rosendale cement now being used in making the concrete for the parapet. The specimens were made as usual and under my personal supervision, so that there is no reason to suspect the workman of not making the briquettes properly. After 1 day in air the specimens were placed 6 days in water and then allowed 1 day to dry, so that the circumstances were most favorable. Notwithstanding this the sand briquettes (2 parts sand, 1 part cement) all broke with the slightest pull with the hands and could be crushed between the fingers. The pure cement did a little better. Four specimens gave 100, 120, 95, and 105 pounds, respectively, a mean of 105 pounds per briquette or 46 pounds per square inch. I think this result very unsatisfactory. Compared with the tests reported by me June 5, 1890, it will be seen that the sand briquettes were about the same quality, while the neat cement seems poorer. On the whole I should say the Rosendale cement possesses very slight hydraulic properties. Very respectfully, your obedient servant, Lieut. Col. W. R. KING, A. M. D'ARMIT, Second Lieutenant of Engineers. Corps of Engineers. RIVERS AND HARBORS, ETC. APPENDIX A. IMPROVEMENT OF RIVERS AND HARBORS IN MAINE AND NEW HAMPSHIRE. REPORT OF LIEUTENANT-COLONEL JARED A. SMITH, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1891, WITH OTHER DOCUMENTS RELATING TO THE WORKS. 30. Establishment of harbor lines at Lu- 31. Establishment of harbor lines in Ken bec, Maine. nebec River at Bath, Maine. UNITED STATES ENGINEER OFFICE, Portland, Me., July 9, 1891. GENERAL: I have the honor to transmit herewith annual reports for the fiscal year ending June 30, 1891, for river and harbor works in my charge. In carrying on these works I have had the very faithful and able assistance of Mr. A. C. Both and Mr. F. S. Burrowes, assistant engi IMPROVEMENT OF ST. CROIX RIVER, MAINE. In compliance with requirements of the river and harbor act of August 11, 1888, an examination and survey of the St. Croix River was made in 1888 and 1889, and a report, with plan of improvement and estimate of cost, was submitted by the engineer officer in charge. (See Report Chief of Engineers, 1889, p. 463.) By act of September 19, 1890, Congress appropriated $35,000 for the improvement, "upon the condition that the government of the Dominion of Canada shall expend a like sum in the improvement of the said river." As it is not yet known what action the Dominion government is disposed to take in this matter, no steps have been taken towards the expenditure of the appropriation. A regular line of steamers plies on the river and St. Andrews Bay, running in connection with the International Line of steamers which run between Boston, Mass., and St. John, New Brunswick. The freights in sailing vessels are very large (principally of lumber), but it has not been practicable thus far to obtain exact statistics. Much the greater portion of the freights are shipped and received on the west side of the river (i. e., in the State of Maine). Money statement. Amount appropriated by act approved September 19, 1890 Amount (estimated) required for completion of existing project... 245,000.00 |