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32 4° Wly. Find north on the left hand margin of diagram ard follow the hori- zortal line coincidirg with it to the magnetic line. From this magnetic line count 4 degree spaces or squares to the left of the magnetic line because the deviation is westerly, and make a dot. On NW we will say, for example, that the deviation as found from our range is 7° Wly, Find. the horizontal line on the diagram coinciding with thé com- pass point NW and beginning from the magnetic line count 7 degree spaces to the left and make a dot. On W by S we will say that the deviation as 'found from our range is 3° Ely, Find -the horizontal line coinciding with the point W by S on the card and follow it out o :. the magnetic. line, and from the magnetic lire count three degree spaces to the right of the magnetic line on account of the deviation being easter- ly instead of westerly, and make a dot. On SW x W the deviation as found from the range is, we will, S4¥ x, cus , Ely... FindeSW x W on, the card 'and. run, gut. " on the Horizontat 'line coinciding with it till the magnetic line is"réached. Then at from the magnetic liné on the same hori- zontal line count 6° spaces to the right of the magnetic line and make a dot. Now draw a smooth curve through all the dots. 'This line represents the devia- tion curve, and where the curve cuts the magnetic line there is no deviation at all; To find on which point of the compass this corresponds run in on the _ horizontal line at the point of contact and see which point of the compass it coincides with on the left hand margin of diagram compass and that will be the compass point on which there is no deviation. To find the deviation corresponding to any point between the points we have ob- served the deviation for as above, mere- ly find the point of the compass at the margin of the card you desire the de- viation for, and follow the horizontal line coinciding with it to the magnetic line. Then from this magnetic line count the number of degree spaces to the curve drawn and you have the amount of the deviation corresponding to that poirt of the compass lying directly abreast of it. If the deviation curve lies to the right of the magnetic line the Dey. is Ely., if to the left of the mag- metic line the Dev. is Wly. Of all methods what is more simple than the foregoing? It is simplicity in itself. We have established the fact that from four range bearings in going up the Soo river we are, by the aid of Bax- ter's diagram, enabled to find the devia- tion on every point of the compass inits western semi-circle, which is equal to saying that we can 'allow the proper cor- rection to any course "up" Lake Supe- rior. There is no other "graphic meth- "en and the THe Marine REVIEW od" which is so simple as that of Bax- ter's, sirce all others require some in- strument for measuring, whereas in this method you merely count' off-handed. The method is so obviously plain com- pared with others that an error in your work can hatdly occur. Bound down the Soo river the ship- master can by the same method and from the same ranges (by reversing the correct magnetic ranges as given above) find the deviation of his compass for the eastern 'semi-circle, affording a means of allowing the proper corrections to the correct magnetic courses to Lakes Erie and Michigan:ports. ..From; first appearances: Baxter's diagram -ilooks. to!,beo.a complicated affair, but this is' only apparentsince it is much more simple than,.it: looks: If, shipmastersowill only igive'/this' de+ vice a fair trial and dewoteca little of the'r spare time to a study of its merits they cannot but help finding -it so... It would seem~to us that so _ valuable a. device should find its way on board 'of every vessel afloat, and owners should buy them by the doz- see to it that their boats supplied with them and_ that master tse them for the pur- pose intended. Further, that this valuable method should be brought to the attention of the, Supervising Inspector General of Steam Vessels with the idea of embodying it in the examination work for lake captains. This the were method of ascertaining Deviation of the Compass should be employed by the master at all times. Jt should. be employed as a check 'by those shipmasters acquainted with azimuth work used in , conjunction with Fields' Course Corrector, or other bearing instruments of this character. The sun may be overcast for days at a time rendering it im- posible to take the required obse-- vations. Every shipmaster of ability is continually on the lookout for op- portunities of this kind. This range 'method will likewise act as a proof in your azimuth work, and the two together. will make you doubly sure of the accuracy or inaccuracy of your work. BAXTER'S "GRAPHIC METHOD." A most ingenious and valuable de- vice has been invented lately by Cap- tain' John "Baxter, for many years captain of the U. S. Lighthouse Tend- er 'Haze. Wile the invention: it- self bears a recent date it, neverthe- less, captain in plotting laying down his courses, his bearings, converting courses from magnetic .to. true. or compass and vice versa, calculating his deviations of compass on has been used for years by the . the different courses, and plotting his curve of deviations from a few ob- servations. Indeed, the limit. of its possibilites has not yet been reached, for the captain is continually dis- covering new uses for it of which he never dreamed. At first he used it simply for the conversion © of courses and _ bearings. The -- In- spector of the Lighthouse District, a naval officer of long experience in navigation, 'with the greatest inter- est watched 'the captain' use 'his simple instrument, and after proving to his own' mind °that!< the° instrument is mathematically correct, strongly ad- vised that it be patented and then placed on the market for the benefit of all navigators. This device is for the purpose of solving tfihy of the simple problems of navigation which daily confront the master and pilots of all lake or ocean craft. In laying down courses so many disasters-have resulted from a mistake being madé in applying the deviation or variation the wrong way, even when the master had per- fect knowledge of the rules of such application, that a mechanical device which is absolutely correct under all circumstances, should be viewed with much satisfaction by all navig- ators. The human mind' is liable to error, but a machine which is. correct in the first instance will never make a mistake. It will be noted that 'instructions for the use of the device are printed On. the back. - Besides these there 'are practical examples, dealing with near- ly every possible condition, worked out for the guidance of the. navigator. The examples alone are of great value as aids in obtaining courses or bearings under like conditions, especially if the master is 'in any doubt as to the correct way to apply the corrections. If the device were of value only for the purpose of finding the de- viations on the different compass courses it would. be well worth all that is asked for it. A few obser- vations on _ practically equidistant points around the. compass will be sufficient to plot the curve of devia- tions. Two curves should be made, drawn in different colors, one for deviations when running light and the other when. loaded. ' In cases where there is very little deviation the curve can be distorted by letting two or more degree-spaces on the card represent one degree of deviation of the ship. For instance, suppose the maximum deviation in our table is 5 degrees W. Instead of counting off only five spaces to the