RECAPITULATION FOR THE SUPPORT OF THE BUREAU OF NAVIGATION. A- I. Salaries, Bureau of Navigation Salary (submitted) B- I. Salaries, Office Naval Intelligence.. Salary (submitted) CI. Salaries, Office Naval Records of the Rebellion. Salaries (submitted) II. Stationery and contingent (submitted) D- I. Salaries, library, Navy Department.. II. Books, library, Navy Department. Professional books and periodicals (submitted). E- I. Salaries, Hydrographic Office... II. Contingent and miscellaneous expenses. F- I. Salaries, Nautical Almanac Office GI. Salaries, Naval Observatory Salaries (submitted).... II. Contingent and miscellaneous expenses. Statement of the amounts expended at the different navy-yards under appropriation establishment, 1887-'88" (third section, act January 30, 1885. 66 Civil $1,000.00 4, 770. 40 999.99 1,199.99 1,000.00 8,970.39 REPORT OF THE SUPERINTENDENT OF COMPASSES. BUREAU OF NAVIGATION, NAVY DEPARTMENT, Washington, October 10, 1888. SIR: I have the honor to submit the following report of the work performed in the Compass Office during the past year. In November last the twenty-six 74-inch compasses mentioned in my last report were inspected, and in August ten more 7-inch and thirty boat compasses which had been repaired this year were inspected and passed. They conformed to the high standard of test now applied to all navy compasses. Eight azimuth-circles which were damaged by fire in the New York navy-yard were repaired. Messrs. Ritchie & Sons are now making six new azimuth-circles of the standard pattern. A novel form of azimuthcircle was presented by this firm for experiment. It was sent in March last for trial in the U. S. S. Pensacola during a cruise in the West Indies. The results of this trial were submitted in a special report to the Bureau by Capt. A. R. Yates, U. S. Navy. In view of this favorable report and the celerity with which the instrument can be used in all ordinary weather, I recommend its issue to the vessels of the Navy. One magnetometer of the Fauth pattern was sent to the U. S. S. Ranger. An exhibit of instruments belonging to this office was sent to the Cincinnati Exhibition. Various new devices bearing on the subject of compasses have been examined, but none seemed of sufficient importance or practicability to suggest their adoption in the service. Compass reports have been received from the cruising vessels, the calculations verified, and the results filed. Two Thomson's vertical force instruments, three clinometers (Evelyn's patent), and one Pelorus were purchased abroad. It is the intention to issue the Pelorus to ships in place of the Alidade or dumb compass, which has no gimbal attachment. During the year all the compasses of obsolete pattern and those of the new type needing repairs have been sent to the Boston navy-yard, and I respectfully suggest that hereafter all compasses and binnacles for issue be stored at the New York and Mare Island navy-yards. Tell-tale compasses being useless on board steel or iron ships unless compensated, I would recommend that their manufacture for the Navy be discontinued. The Messrs. Ritchie & Sons were the successful bidders for making ten compensating binnacles for the new cruisers. The internal mechanism for moving the bar-magnets has been altered, and is believed to be an improvement on the arrangement as heretofore used. The essential features of the two binnacles, however, are alike, eight magnets being used in each case. A new device for holding the heeling magnet has also been introduced. Two of these instruments have been finished and inspected, and are now in store at the New York yard ready for issue. The old binnacle was thought to be too heavy. In the new one the weight has been considerably decreased. Experiments are now making with the view of increasing the illumination of the compass, a device being sought by means of which the light from the binnacle lamps may be concentrated on the keel-mark of the compass bowl. MAGNETIC DIRECTION OF SHIP'S HEAD IN BUILDING, N. 43° W. [Report of Secretary of the Navy, 1888- Navigation.] Abroad, binnacles with two sets of magnets, one being fore and aft, and the other athwartships, are being generally used. With the view of getting a very light binnacle for use on board our small vessels, a binnacle was made at the Washington navy-yard in which magnets are placed as stated above. Experiments with this instrument were undertaken in this office on the model Scoresby, and proved that the binnacle as made was efficient. It remains in the Compass Office, and should a very light binnacle ever be required for torpedo boats, it may serve as a pattern. The magnetic headings of all the ships now building for the Navy have been observed, and as far as possible observations have been made to determine their magnetic character. At the yard of William Cramp & Sons the vessels were built in such close proximity to each other that reliable observations were impossible. Work of this character has, however, been done on board the Yorktown and Vesuvius while fitting out in the slips, and lately some preliminary observations have been made on board the Baltimore on the stocks, the vessels which were alongside of her having been launched. On board the Petrel observations were also attempted, but as she is a small vessel it was found that the results were probably vitiated by her proximity to the pump-house of the graving-dock at the Columbia Iron Works. The records of all these observations have been placed on file in this office, where they are of easy reference, and when completed will form a magnetic history of these steel vessels. A drawing of the Vesuvius, showing her magnetic forces and their directions at different stations, is subjoined to this report. In this connection I would suggest that it is almost imperative that a clause should be introduced in contracts made with the builders of our steel cruisers, requiring ships to be fitted out with head opposite to the direction of building, and that all metal fittings in the vicinity of the binnacles should be of bronze as far as possible and not of steel or iron. In June, Lieut. G. W. Denfeld and I proceeded to Erie, Pa., and swung the U. S. S. Michigan for compass deviations, and with a Flinders-bar partially compensated the compass in the wheel-house, which had always given trouble owing to its large deviation, the maximum being 260. Her standard compass, as now placed well aft on the poop, has only small deviations and does not need compensation. The Chicago's compasses were recompensated while the vessel was alongside the dock in the New York yard, a large amount of ballast iron having been put on board previous to her speed trial. In the position selected for her standard binnacle on the after bridge, the compass is affected by the magnetic field of the dynamos. Another position further aft, on a platform to be built on the quarter-deck, will probably have to be selected. As suggestive of the necessity for frequently observing the errors of the compasses even on board wooden vessels where sometimes the com passes are unavoidably placed near the funnels, I would refer to a special report on this subject made by Commander B. H. McCalla, commanding the U. S. S. Enterprise. On board the Enterprise the steering compass in the wheel-house is quite close to the funnel and is compensated by means of a Flinders-bar. Commander McCalla reports that during a four-hours' speed trial in the Gult of Finland when the funnel was heated more than usual, although the standard compass aft showed no change in the heading, that of the steering compass above referred to changed from S. 810 E. to S. 86° E. at the end of the four-hours' run. |
