I am, myself, employed in collating and translating into English the rules and formula for the determination of an orbit from three complete observations. The recent numerous discoveries of small planets bring these rules into frequent use. I propose to publish my translation, under the sanction of the department, in the same form as the pamphlet on special perturbations, of which a copy was transmitted to Washington. The ephemeris of the planet Neptune, and that of Iris, for the year 1852, have been published by permission of the department; the former in the Smithsonian Contributions. In my letter of August 11, I had the pleasure to inform the department that the observations of the solar eclipse of July 28 had proved, in a striking manner, the accuracy of the predictions given from the office of the Nautical Almanac. After having spent so much labor in compiling the auxiliary tables, by means of which it was expected that the moon's place would be given with greater accuracy than by the tables used in the calculation of any one of the published ephemerides, it was highly satisfactory to have this expectation confirmed by such a strict test as the late solar eclipse. As examples of the superior accuracy of our methods, I may adduce the following cases: Here, the beginning of the eclipse, according to the elements of the British Nautical Almanac, should have taken place at seven hours forty-eight. minutes and ten seconds; according to our calculations, at seven hours fortynine minutes and thirty-five seconds; that is, the British Almanac was in error eighty-five seconds, and the American Almanac twenty seconds. In the predictions for the Washington Observatory, the difference between this office and observation, (the observations were made by Professors Hubbard and Ferguson, and communicated by Lieutenant Maury,) was thirteen seconds at the beginning, and one and a half seconds at the end. In the case of Dantzic, where the eclipse was total, and where, for this and other reasons, the test was more rigid and conclusive, the errors of the British and American Almanacs for the different phases were as follows: As these tables were computed and arranged under the immediate direction of our distinguished astronomer Professor Peirce, I may, without fear of being thought egotistical, express the very great satisfaction felt by all astronomers in America at this brilliant success. The same tables of the moon are used in the French and Berlin Almanacs as in the British. The errors, therefore, are the same. The practical value of our corrections and improvements is shown in their effect upon the determination of the longitude at sea, by means of lunar distances. The errors of the European ephemerides may create an error of from fifteen to twenty miles in the longitude, and an uncertainty, therefore, of twice that amount. The possibility of this error will be removed in the American ephemeris. I have before said that I should have the honor to submit a full report on this interesting subject, as soon as the materials for it are collected. But the European observations are not yet all received in an authentic form; and of those received, but few have been fully discussed, owing to the pressure of other occupations. I have now to make known to the department another source of gratification concerning the moon's ephemeris. Mr. Miers Fisher Longstreth, a merchant of Philadelphia, a lover and student of the science of celestial mechanics, after devoting several years to an investigation of the differences between the computed and observed places of the moon, and to the means of correcting the serious errors in the lunar formula, has, by an empirical process, introduced such further improvements as now enable the computer to predict the moon's place in the heavens with a degree of precision, which, compared with anything heretofore attained elsewhere, is truly extraordinary. The first number of the Almanac will exhibit the advantages, and enjoy the distinction, conferred by these honorable and successful labors. Our work has been somewhat retarded by the necessity of applying Mr. Longstreth's additional corrections; but for this we are more than compensated by the increased accuracy, and by the opportunity afforded to the men of science in America to repay the liberal patronage of the government, by assisting to render this work in every way creditable to the country. Very respectfully, your obedient servant, CHARLES HENRY DAVIS, Lieutenant, Superintendent Nautical Almanac. Hon. WILLIAM A. GRAHAM, Secretary of the Navy, Washington. No. 2. NAVY DEPARTMENT, BUREAU OF CONSTRUCTION, &c., November 1, 1851. SIR: I have the honor to submit, in conformity with your instructions, estimates for the fiscal year ending on the 30th day of June, 1853, embraeing that portion of the naval service coming under the cognizance of this bureau, accompanied by statements exhibiting the rates and distribution of the vessels belonging to the navy of the United States in commission on the first day of November, 1851, the number and rates of those in ordinary, those on the stocks, the building of which have been suspended for many years, and those undergoing repair; also exhibits of the estimated value of articles received and expended, with the amount and cost of labor upon objects connected with this bureau at the several yards during the same period. The value of articles on hand at each, at the commencement and close of the year, is shown in the table containing the amount of receipts and expenditures, a schedule of which is annexed for reference. The estimates for construction, equipment, repair, and armament of ships, coal for steamers, hemp, &c., are reduced to the lowest amount at which a force equal to that now employed can be maintained. Since the last annual report, the number of ships necessary to keep up a force equal to that of the previous year, upon which the estimate was based, have been equipped, and proceeded to their respective stations. Among the number was the steamer "Susquehanna," now on her way to the East Indies. Her qualities as a sailing vessel and steamer are satisfactory. The propeller "San Jacinto," on her recent trial trip, gave promise of being an efficient steam-vessel. The steamer "Princeton," at Boston, "Fulton," at New York, and "Alleghany," at Norfolk, are in a state of forwardness, and will soon be added to our steam navy. The first-class steamer "Powhatan," launched in February, 1850, is yet detained, in consequence of the non-completion of her engines and machinery. In its last annual report the bureau recommended, as a matter of economy both in time and money, that the engines and machinery for government steamers should be manufactured at our public establishments. The opinion then expressed has since been decidedly confirmed. The bureau would therefore again respectfully recommend that the principal naval establishments be furnished with the requisite machinery for building and repairing steam-engines for the navy. The Washington yard is supplied with all that is necessary for the construction of those of the largest class, and has given evidence, in those already manufactured, of the advantages to be derived from furnishing other public establishments with like facilities for the purpose. The bureau also offered for consideration the propriety of launching the frigates "Santee" and "Sabine," and to furnish one or both with the necessary machinery to drive them by steam. The model of a frigate was prepared and forwarded to the bureau by the naval constructor at Philadelphia, exhibiting in detail the arrangement of engines, boilers, stowage of coal, provisions, water, stores, &c. In order to afford space for the introduction of machinery and bear its additional weight, with the necessary fuel, it was proposed to reduce the armament, crew, water, provisions, &c., and such other weighty articles as could be most conveniently spared. The model, accompanied by the proposition and explanations, was submitted to a board appointed to examine and report upon the practicability and expediency of its adoption into the service. After examining the subject in all its bearings, it was decided by the board to be inexpedient to make the proposed changes, or to apply steam power to sailing frigates of the present dimensions, believing that ships, to be efficient with an auxiliary steam power, should be modelled for that purpose. The " Macedonian," undergoing repairs at New York, will be armed with a single battery of heavy guns, which will render her a formidable vessel of her rate. The "Franklin," a small class ship-of-the-line, recently sent to Portsmouth, N. H., for the purpose of testing the floating dock and railway, requiring extensive repairs, it is proposed to razee, and arm her with batteries of heavy guns, thereby greatly increasing her efficiency as a ship of war. The bureau would respectfully recommend, in addition to our present naval force, a class of vessels capable of mounting heavy guns, of suitable dimensions to afford comfortable accommodations for their complement of officers and men. The small vessels at present belonging to the navy are inefficient in armament, and so cramped in accommodations as to render those on board uncomfortable, and greatly to impair their health. The class recommended would be equally active, superior in every respect, with but a trifling additional expense. The hemp agents at Louisville, Kentucky, and St. Louis, Missouri, au thorized to purchase American water-rotted hemp at their respective agencies, have so far furnished but a small quantity, entirely insufficient to supply the demand. The stock on hand at the rope walk, Boston, is so much reduced, that unless a large quantity is furnished shortly, the department will be compelled to resort to the foreign article to supply deficiencies. The entire quantity of American water-rotted hemp purchased during the year ending June 30, 1851, amounted to twenty-one tons from St. Louis, and one hundred and thirty-five tons from Louisville; one hundred and nine bales of which was destroyed by a steamboat explosion on its passage to New Orleans. The quantity required annually for naval purposes, ranges between four and five hundred tons. That delivered has been generally fair, and of standard strength. With more experience in the preparation, we may reasonably expect an article equal at least to the best obtained from foreign countries. The ropewalk at Memphis being now in a condition to commence operations, it is proposed to ship the whole or part of the hemp purchased at the agencies, to that place for manufacture. I am, sir, respectfully, your obedient servant, To Hon. Wм. A. GRAHAM, CHAS. WM. SKINNER. Secretary of the Navy LIST OF TABLES. A.-Estimate for expenses of the bureau. B.-Estimate for pay of persons employed in vessels in commission. E.-Statement of vessels in commission. G.-Statement of vessels on the stocks or building. H.-Statement of vessels broken up, or lost. I.-Statement of receipts and expenditures. J.-Statement of the number of days' labor, and its cost. |