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

MARINE REVIEW. a7 point to another upon them. A navigator can lay down any desired route upon his own chart of the great lakes so readily that there is no real need for the services of the chart constructor in the matter. It is the facility offered by the Mercator chart in this respect that has made it the seaman's chart. The tools in universal use with the charts, as you know, are as fol- lows: A parallel ruler, say 18 inches long; a pair of dividers, say 6 inches long; asharp pointed pencil, andarubber eraser. Let us assume that it is desired to project a route from a point of departure, A, toa point of destination, B. MHereisthe simple rule: Align an edge of the parallel ruler on the points A and B and connect the two points bya straight line. This pencilled line--the route in fact--is the well known rhumb line of the Mercator chart. It makes a constant angle with suc- cessive meridians. Move the parallel ruler in a way to preserve parallel- ism to the nearest compass rose, so that an edge of the ruler shall be in contact with the center of the rose. Where that edge cuts the true com- pass of the rose, read the true course (course by true compass) from the beginning to the end of the route. So far, the Mercator chart gives a more favorable result than any other chart, because of the peculiar prop- erty of the rhumb line. To obtain the true course on any part of the chart, any true compass of the chart may be used. If there were any changes of magnetic variation shown on the chart between A and B, an intersection of the edge of the ruler with the magnetic compass of the compass rose nearest to A would give the magnetic course all along the route, but unfortunately for actual practice on the great lakes the mag- netic variation changes rapidly on nearly all the important routes; there- fore, to mark down any long route and to set down thereon a single mag- netic course to be steered all along the line, would be to endorse a prac- tice that might lead to very dangerous results. Perhaps long, straight routes might be subdivided into parts and the magnetic course given for each part, but there would still remain the question of local deviation. So, after all, routes printed on charts have but little more merit than to show mariners the ordinary lines of travel. Distances also may be measured very simply by stepping off along the route intervals taken from the scales at the sides of the chart; namely, scales of latitude, never from the scales of longitude at the top and bot- tom. If the interval is taken from the latitude scales, which now appear on all the charts, the measure will be in nautical miles or knots; if taken from the new side scale, which is to be added, the measure will be in statute miles. It should be noted that the interval taken from the side scales must be taken near the middle latitude of the route or part of the route to be measured; that is to say, to measure the whole route from A to B, the interval must be taken near the middle latitude between A and B; if the diatance is to be measured from A to some intermediate point, C, then the interval must be taken near the middle latitude between A and C. I quote the simple direction already given by the chart: '"Dis- tances may also be measured by taking between the points of the dividers a small number of divisions near the middle latitude of the line to be measured and stepping them off on that line." On harbor charts it is nautical practice to occasionally print routes in channels or fairways, together with courses and range lines, it being recognized that a vessel may lack time in a channel way to measure dis- tances and lay off courses. If I were fully convinced that there is a gen- eral opinion among navigators of the lakes that routes should be printed upon the general charts of the hydrographic office, I should certainly conform to the general desire, but I wish to get ample evidence before I depart from any well established standard. I would prefer that the office should project by hand, upon any navigator's chart, any special route or routes that he may desire. Either the main office or the branch offices will undertake to discuss and project any desired route for any applicant. The navigators of the great oceans frequently make application to be informed of the best meterological routes for particular seasons from one part of the world to another. The hydrographic office has much evidence that at least a large body of the navigators of the lakes look beyond the mere consideration of one or two peculiar details of a chart and discern plainly back of the charts the prospective benefits of the whole system. The work of the office being comprehensive and nautical in character, it does not stop with the publication of the chart alone, but connects therewith "Sailing Directions" containing much statistical and descriptive infomation that would be superfluous on the charts; light lists to give information relat- ive to light-houses and light-ships; " Notices to Mariners," by means of which publications may be kept corrected for the latest information, to- gether with special publications from time to time, and branch hydro- graphic offices, which afford for the use of navigators in general a com- plete library of charts, 'Sailing Directions," etc. In addition, the office holds forth the promise to investigate for applicants questions relating to navigation, etc. The office has invited suggestions from many of the ablest navigators of the lakes and has received and acted upon their suggestions. The correspondence of the office in this respect has been very great. I recognize that it is frequently difficult, in pursuing a lake route, as from A to B, to determine intermediate positions of the vessel, owin g to the absence of visible land marks. This does not necessarily point to a modification of the charts, but does it not indicate the desirability, now that charts and other printed publications are available, of extending the use of nautical instruments on the lakes? Navigators who are well sup- plied with instruments of navigation do not feel an undue dependence on light-houses, buoys, ete. Light-houses and buoys should always be ample in number, but with or without them, instrumental methods relieve navigators from anxiety and tend greatly to the safety of the vessel. Undoubtedly, the best methods of navigation are those which enable the navigator to control the situation with his own means and with a minimum of outside assistance. The best practice on the oceans and the seaboard in navigating a route of considerable length, say from A to B, is as follows: 'The vessel, proceeding from A, first obtains from the nearest compass rose of her chart her magnetic course at A; applies the local deviation of her com- pass thereto, and steers the resulting compass course. After proceeding some distance, which varies according to circumstances, she finds her position again by one method or another. She finds it by means of astro- nomical observations, or by compass bearings of objects on shore, or by one bearing and asounding only, or bya single sounding, or by pro- gressive soundings, or by measuring angles at the ship between objects on shore, or by ranges or otherwise; but having determined her position, she probably finds herself somewhat off the original route. She does not then, as arule, endeavor to get back on the original route, but by the method pursued at A, shapes a new course for B, or because of altered circumstances, some new point near B. Since I recognize this as the best practice, you will understand more clearly why I hesitate to print fixed routes upon the charts. Having commanded four sailing ships and two steamers and having had practice in piloting very unexceptional both in extent and variety, I speak from experience in discussing these matters. Ican not conceive myself as desiring that anybody should dictate my route in any place where there is ample water, assuming my- self to have a sufficiency of charts, sailing directions, and other instru- mentalities relating to the locality to be navigated, Moreover, it seems to me that all persons who use the hydrographic office charts strictly for navigating purposes must feel similarly. I find it difficult to bring forward on paper what I might say without hesitation in conversation, but perhaps you will not take it amiss ifI suggest that sextants and certain kinds of protractors for finding ships' positions might prove very beneficial on the lakes in connection with the charts, if those instruments are not already used. Over long routes out of sight of land, the navigational sounding ap- paratus, for use with piano forte wire, would be invaluable for determin- ing positions, or at least for indicating the set and driftof the vessel. With this apparatus, Atlantic liners get soundings in depths as great as 600 feet (100 fathoms) without stopping the engines. The value of sextants and protractors is that the positions obtained by them from land marks are entirely independent of the question of variation and deviation of the compass. There used to be a not uncommon idea among shipmasters on the seas that there was considerable merit in navigating ships with an insuf- ficiency of means, but I think that sentiment has about passed away, and I assume that it does not exist on the great lakes. C. D. SIGSBRE. Stocks of Grain at Lake Ports. The following table, prepared from reports of the Chicago board of trade, shows the stocks of wheat and corn in store at the principal points of accumulation on the lakes on Jan. 4, 1896: Wheat, bushels. Corn, bushels, ChicagOscsccscsnsssvere eee seins seaepesteas 21,192,000 1,099,000 Dralithiis.c.. tb heaves cosaworcerertenres 8,763,000 8,000 Milwaukee. .i.s6s.c7.sicsvesrereceeetessneb ss 440,000: mi CRS aa eee Detroit: .¥acscdervuveccecoeste ore eeeeuenarss 367,000 - 18,000 Mole O'srizsges.dsetes]occrsneweateeseenerenaeee 872,000 171,000 Brita of: sscieceie todiesse+-puwusecaies eas ee 3,103,000 114,000 T Otel aasevncncaseseas sasver recur 34,737,000 1,410,000 As compared with a week ago, the above figures show at the several points named a decrease of 373,000 bushels of wheat and an increase of 161,000 bushels of corn. On Jan. 6 there was afloat at Chicago 449,000 bushels of corn and 86,000 bushels of oats; at Buffalo, 259,000 bushels of wheat, 223,000 bushels of oats, and 304,000 bushels of barley; at Duluth, 512,000 bushels of wheat; and at Milwaukee 176,000 bushels of wheat and 120,000 bushels of oats. Secretary HamiltonJ. Mills of the Dry Dock Associatign of the Lakes announces that the annual meeting of that organization will be held at Detroit on Thursday, Jan. 16, the day following the annual meeting of the Lake Carriers' Association.