The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

3? - He Marine REVIEwW SCIENTIFIC LAKE NAVIGATION SOME PRACTICAL EXAMPLES. Now, we will take some practical ex- amples which come up in every-day lake navigation: The lighthouses of Frying Pan and Pipe islands range true N 3% W, variation for that locality 4° Wly. How should your compass read when on with this range if there were no deviation, or what is the c. m. bearing of this range? Answer north; 4°, for all practical pur- By Clarence E. Long ought to read when on with this range provided there was no deviation? An- swer, E 3 S. For practical purposes 6° equals 14 point, and as the variation is Wly. allow to the right, and 4 point to the right of E% NisE%S._ The true bearing of the Milwaukee piers is E % N, variation 3° Ely. How had your compass ought to. read if it were correct, in going out parallel with piers. Answer, E % N 3° is equal to 14 WHEN SOUTH IS MADE THE TOP OF THE COMPASS. Showing westerly variation (1-point). outer compass? shows the true points of the horizon at any place. and is herewith republished in corrected form. poses, equals 36 of a point, and as the variation is Wly. it is allowed to the right of the true bearing, and % of a: point to the right of N 3% W is north. The c. m. back range (over stern) of these lights would be south, the true range being S % E. Whe St Clair Flats canal runs true N E % N and S W % S, the variation for that locality being 1° 30' Wly. What is the correct magnetic course through the canal, or in other words how should your compass read if there were no de- viation? Answer N E % N; 1° 30' be- ing practically % of a point, and it be- ing Wly. is allowed to the right; and % to the right of NEX NisNEYN. The reverse direction correct magnetic would be S W &% S. : The true bearing of the lighthouse on the north end of Buffalo breakwater when in range with the lighthouse on the south pier at the entrance to Buffalo, is E % N, variation 6° Wly., what is the c. m. bearing, ar how had your compass TRUE POINTS op Is not the inner compass turned to the left of the The inner compass is affected by variation only while the outside compass This cut was incorrectly assembled last week point, that is, it is nearer to %4 point than anything else; and % point to the left (the variation is Ely. in this case--allow to the left) of E.%4 N, the true bearing of these piers, and this is the way your. 'compass should read going out of there to be correct. rEED The true bearing of the Duluth harbor piers is S W by W:.%-W, variation 8° Ely. How had your compass ought to read when in line with the piers going in; or what is the c. m. bearing of these piers? Answer, S W by W &% W;; 8° is nearer equal to 3%4 of a point, and as the variation is Ely. and allowed to the left, therefore moving to the left of S W by W % W true brings S W by W % W correct magnetic. CORRECTING COURSES BY THE NUMBER OF THE POINT IN EACH COURSE. This system of notation recommends itself as a handy and convenient method of correcting courses, and the conversion of. one kind into another; and more es- pecially where it is required to keep a record course sheet, and also in this kind of work in the examinations before the board of steamboat inspectors. In the chapter on the compass we made the student acquainted with the significance of these terms and showed him the reas- on and principle for so naming them; and too, called attention to the import- ance of familiarizing himself with same. The points of the compass are fre- quently spoken of in calculation with reference to their position to the RIGHT or LEFT of the cardinal point towards which the spectator, who is supposed to be placed in the center of the com- pass, is looking. Supposing the given point of the com- pass to have north in it, then looking from the center of the card over the eardinal point north, he has the quad- rant from north to east on his -right hand, and the quadrant from north to west on his left hand; thus, N E is said to be "four points" to the right of north, and NNW "two points" to the left of north, and so on. Again, suppose the given point of the compass to have south in it, then the observer looking from the center of the card and facing south, has the quadrant from south to east on the LEFT hand, and the quadrant from south to west on the RIGHT hand; thus, SE by S is said to be "three points" to the LEFT of S, and W by S is "seven points right of south," and so on. Hence, any point or degree between north and east is said to be to right of north; and between north and west to the left of north; and between south and east to the left of south; and between south and west to the right of south. For example; NNE is two points right of north (for shortness written 2 points (pts) R of N) and WNW is six points left of north (6 pts. L of N); SE by Sis a pts of Sand W by S is 7 pts. R of S. GET FAMILIAR WITH THE COMPASS CARD. The learner should so familiarize him- self with the compass card as to be able to turn the name of the compass point of any course into its numerical value, or the number of degrees corresponding thereto, instantly, and when you have ac- quired such knowledge, you will find the following rule serviceable. Rules: Put down the points and quarter points which the true course is to the right or left of north and south, marking them R or L accordingly. Underneath put the variation, marking