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and starboard shafts respectively; and - armature of the latter magnet is connect- gins of the tape. . The instrument will run out 125 feet of “tape with very little variation of speed. -'Phis with the inch per second governor {0 WEAVER SPEED RECORDER. (ILLUSTRATED ) The Weaver Speed Recorder was especially designed by W. D. Weaver, Esq., formerly of the Engineer Corps U.S. Navy, to carry out a method for trial-speeds advo- . cated by engineer-in-chief Melville, and was successfully applied on the trial of the U.S. S. “Bancroft.” What exactness is desirable in trial-speeds may be judged from the facts that premiums amounting to over $30.00 per foot or $1,100.00 per second have been paid by the navy department. This instrument makes a permanent and accurate record of each revolution of the screw; of each second of time; and of starting and leaving the range. This record is made on a paper tape, on which the central line of dots represent the seconds; the marginal dots, the entry and leaving the range; and in a twin-screw vessel, the intermediate ones would be the revolutions of the port and starboard screws. There is a clock mechanism inside the case, by means of which the paper tape is passed over the pens which make a mark at each electrical contact. The clock mechanism has a Geneva 2 stop so that the speed is as regular as possible. There is also a government attachment, by which the tape can be regulated to move at the rate of a half-inch per sec- ond; inch per second; or inch and a half per second. _ The tape moves freely over the six pens, which are actu- ated by five magnets; to one of the magnets is led the interrupted current of the chronometer; to three others the currents are estab- lished by contacts on the port, midship, through the fifth a momentary current is passed, by the observers, at the instant of reaching and leaving the range. To the ed two pens, which mark on the two mar- corresponds to the time of about 25 min- utes. The tape may be measured to give ae) ‘hundredths of aninch, and with the shaft making 120 revolutions per minute, 50ths of the revolution. An es- ‘sential feature isthe ‘‘piano action,” of the pens; through this, the time of contact of the pen is infinitesimal, thereby avoiding friction against the tape at a critical moment. A range observer, for example, can keep the key depressed after passing the range, but the pen will drop free from the paper, after instantane- ously having made its mark. 1: Before a trial trip is made, the instrument is put ina convenient part of the vessel, and the magnets con- nected respectively, one with an electric break circuit chronometer with a special seconds break on. The relay between the chronometer and recorder is used so that a small current may be used in the chrono- meter, and so that the recorder magnet will have a “make cireuit.”’” Another magnet actuating the two marginal pens is connected with the range contact makers. These makers are held by the observers, who EED RECORDER THE MARINE RECORD. a press one button which rings a bell just before they reach the range; and press another button the instant they come on thé range. There is an observer in the bow and another at the stern of the vessel. The other magnets are connected with the shafts of the vessel. The instrument is adapted for a single, twin or triple screw steamer. When the observer rings the bell, the instrument is started, the tape moving freely over the pens, and each second beat of the chronometer is marked on the tape, and also each revolution of the shaft. On reaching the range, the observer makes a contact with the marginal perts which designate the beginning of the range; he again makes acontact which designates the end of the range. A datum line is made by drawing a line across the tape between the two mar- ginal dots. The seconds are then counted, and the num- ber of revolutions counted for each shaft which gives the required data, to ascertain just what the vessel has done. Experimenting at different speeds where the distance and force of tide are known, enables the engineers to get records to standardize the screw by which they can know accurately what speed a vessel has made during an ocean trial of four hours when these instruments are used. They can. also be used in launching vessels and on locomotives. They are made by the Wells & Coutan Co., Ltd., New York. Beatie seis erie estes torre RAILROAD CAR FERRIES. It is reported that the Chicago, Milwaukee and St. Paul Co. are about to embark on a steam car ferry pro- ject. They propose, itis said, to ex- tend their Lake Superior division so asto form a junction with the Ahnapee and Western railway, which termin- ates at Sturgeon Bay, by forming a steam ferry connection on the east ‘shore with a trunk line to the seaboard. The Murril, Antigo and Fastern railway and the Wisconsin and Michigan line are also interested in the scheme. The Wisconsin Central railway has completed the purchase ofland at Manitowoc for a lake terminus at that point, and another car ferry line to an east shore port is also regarded as among the possibilities of the near future. Plans have been recently got out for such a line of boats and they are to be ice crushers, so that a winter service can be maintained, DD > + THE MARINE POSTOFFICE AT DETROIT. On Wednesday, June 19, 1895, the United States ma- rine postoffice was opened at Detroit by order of the postmaster-general, and began the delivery of mail, in- cluding registered matter, to all boats passing Detroit. The success of the marine service will, in a large measure, depend on the co-operation of the vessel in- terests, and, as this service has been established almost solely for the benefit of those interests, their hearty co- operation is confidently relied upon. With their support it isanticipated that the benefits that will accrue to the lake marine interests from a mail service which will be prompt, certain and reliable, will quickly become man- ifest and will be immediately taken advantage of by all concerned in lake navigation. It will be necessary for the vessels desiring to receive or deliver United States mail to enter the American channel, but only at the point of delivery. The marine postoffice station will be located near the ferry landing, between Woodward avente and Bates street, and deliveries will be made as nearly opposite that point as possible by a launch and small boats ; the service being a continuous one, night and day. The delivery of telegrams through'the mails may be had by attaching a two-cent stamp to the telegram, and for immediate delivery, the addition of a special deliv- ery stamp. Mail for delivery by the marine postoffice should be directed to the ‘‘ Marine Postoffice, Detroit, Mich,’’ and deliveries will be made throughout the entire period of navigation. During the close of navigation the station will be kept open for the accommodation of seamen re- siding at Detroit. The postmaster at Detroit calls the attention of mas- ters and officers of boats to the following code of signals and the masters are requested to have the code posted in a conspicuous place upon their boats. Signals to passing boats from U. S. mail boats for de- livery of mail: Blasts—One long, one short, one long. Signal for steam vessels wanting mail boats to call for mail: Blasts—One long, one short, one long. : Signal for sailing vessels requiring mail boat: White flag by day, flashing bright light at night. Signal from mail boat to large boats to check down: Three blasts of mocking bird whistle. Signal from rowboat belonging to mailboat when ap- proaching vessels for delivery of mail: White flag in daytime, swinging bright light at night. — ED OD AMPL!TUDES. The following approximate amplitudes of the sun’s rising will be given each week in this column during the season of navigation. A second bearing of the sun may be taken at sunset by reversing the bearings to read west instead of east, as for example, N. EK. by EB. for a sunrise bearing would read N. W. by W. fora sun- set, or EK. 30° N. to W. 30° N. LAKE ERIK AND S. END LAKE MICHIGAN, LAT. 42° N. Sunrise. Bearing (degrees). Bearing (points). Tire 2 eeas ee ee EB. 32° N. NE. by EK. % E. Tine 2B es UES Rees By. 32° N. NE. by E..% E. LAKE ONTARIO, S. END HURON AND CENTER LAKE MICH- IGAN, LAT. 44° N: Sunrise. Bearing (degrees). Bearing (points). June 2b ee ee 33k Ne NE. by BE. % EB. Jane 28eties Aes EK. 33° N NE. by E. % E. N. END LAKES HURON AND MICHIGAN, LAT. 46° N. Sunrise. Bearing (degrees). Bearing (points). al ga UR Ane E. 34° N. NE. by E. bb Vol A A0 aie yw Er oaw ASAD E. 34°. N NE. by E. LAKE SUPERIOR, LAT. 48° N. Sunrise. Bearing (degrees). Bearing (points). Aly patey?.s Bt se Garten whe EK. 36° N. NE. % E. TUNE 2S oy ee EK. 36° N NE. % E. With a compass correct magnetic, the difference be- tween the observed and true bearing will be the varia- tion for the locality. If there is any deviation on the course the vessel is heading at the time of taking the bearing, the result after the variation is applied will be the amount of deviation on that course. rrr re NOTES. THE battleship Iowa, now building at Cramps, is to be fitted as a flagship. ‘ JAPAN wants more war ships and will probably build some of them in this country. ALL the state-rooms of the leading trans-atlantic steamships have been engaged for several weeks ahead. THE American Line steamer S. Louis, Capt. Randle, from New York for Southampton, made the trip in seven days and two hours. THE Navy Department is considering a plan for re- moving to Philadelphia the old war monitors, which are now lying in the James River, below Richmond, Va. Tue Acting Secretary of the Navy has allotted among the State Naval Militia Battalions the $25,000 appropriated by congress for their aid. Pennsylvania gets $1,518.18. Tue ship-building output of Scotland for April was 28,746 tons, and orders were booked for close on to 40,000 tons. If the May record works ont similarly, a fairly busy summer will be assured.