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24 edge of the card being so far re- moved from the usual lubber line on the wall of the bowl. I provide for this by introducing a special lubber line, or pointer, in close proximity to the card, to represent the ship's head. In a later development I use a ring form of card, as shown in the. illus- tration, marked with degrees and car- dinal points only (Fig. 5). The de- gree divisions can be made so prom- inent that a steersman can readily see them, and these show up better in the absence of the darkening effect of the points and half-points. At first a magnifier was employed to readthe card, but this was inconvenient, espe- cially when using the azimuth instru- ment, and is rendered unnecessary by employing this style of card. It is certainly an innovation to use a card marked with degrees only; but, as steering to degrees is now univer- sally in use, the elimination of quar- ter-points and half-points is of little consequence and not injurious. As the degrees in all cards are nearest the periphery and quite close to the lubber line, this new arrangement should make for closer and more ac- curate steering than formerly. Perhaps the best evidence of the superiority of this class of compass is afforded by the result of experi- ments made by Dugald Clerk, the writer, and others. It was found, with a compass constructed with a card of sufficiently small diameter as compared with that of the bowl, that the card was not deflected apprecia- bly, even if the compass were turned through the whole 360° in a few sec- onds. As the fastest steamers afloat take about 50 seconds to complete a round turn, it is obvious that any disturbance from the turning move- ment of the ship is entirely elimi- nated. A further advantage is, as with all liquid compasses, that magnets of great directive force are employed. With the Thomson and similar com- passes where light cards are used, the magnets or needles are necessarily of small. directive force, as Captain Creak points out in the paragraph from the "Elementary Compass Man- ual" already quoted. But his warn- ings do not apply to this compass in which powerful needles are used, and the periphery of the card is well withdrawn from the wall of the bowl. This is a comparatively robust instru- ménk. 4 ee. Returning to the subject of adjust- ment of the compass: The main rea- son for the adoption of short needles is that, if they are over a certain cause, which lowers the speed. THE Marine REVIEW length, they magnetize by induction the quadrantal correctors. I do not think, however, it is so well known that the Flinders bar sometimes gets magnetized in a similar manner by the semi-circular correcting magnets. In my own experience I came across Fic 6. a case in which there was some ob- scure disturbance of a compass. It occurred to me to increase the dis- tance between the lower end of the Flinders bar and the magnets, when I found that the disturbance disap- peared. To obviate this danger I should like to see the Flinders bar kept separate from the binnacle cas- ing in accordance with the original practice of Captain Flinders illustrat- ed in Fig. 6, where A shows one of the receptacles for magnets, B a quadrantal corrector, and C the cas- ing for the Flinders bar. . It-is a true saying that there is nothing new under the sun, and to- day we have the return of the liquid compass--not in the crude form em- ployed by the Chinese, but construct- ed to suit modern conditions. Naval architects will readily appre- ciate the reasons for the success of this class of liquid compass, as they have to deal with a similar problem in connection with the trial trip of steamers, which must take place in sufficiently deep water, to avoid the drag, due to friction or some similar same way this compass is constructed so as to have deep water all round the card, and also above and below it, in order to eliminate "the drag." I have designed an azimuth circle, as shown in the illustration Chic: 7), which permits of bearings being taken at high speeds--which is not always In the' possible with the form of azimuth most commonly in use--and also with- out removing the binnacle top, an im. * Nol Hic. 7. AZIMUTH INSTRUMENT. portant factor in bad weather. Cap- tain Creak has a similar azimuth cir- cle for taking instantaneous bearings, designed many years ago. (To be continued.) HENRICH'S AZIMUTH TABLES. The Marine Review has received a consignment of Frank Henrich's Azi- muth Tables for the Great Lakes. Since this work was issued it has met with a most favorable reception and is generally regarded as present- ing the simplest and most efficient azimuth tables ever issued. The deci- mal system, which gives results suffi- ciently accurate for practical pur- poses, is used, and all data needed for the finding of true bearing are pub- lished on the same page. This ar- rangement permits of interpolation for any given time both as to latitude and declination without turning the page. The book contains numerous auxiliary tables and maps with com- plete instructions for using them, to- gether with abundant examples for practice. It is considered by compe- tent navigators one of the best me- diums for self-instruction ever issued. Capt. Henrich has received letters of commendation upon this book from H. Coulby, president and general man- ager of the Pittsburg Steamship Co.; GA, Tomliason, Capt: Px He Ube: roth, commanding revenue cutter Tus- carora, and from many vessel masters as well as from the steamboat inspec- tion service. The Wisconsin Engine Co., Corliss, Wis., announces that in addition to Corliss engines of all types they will hereafter build gas engines as well. Charles E. Sargent will be the engi- neer of the gas engine department. The company controls Mr. Sargent's patents on internal combustion en- gines.