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THE MARINE RHCORD. 7 Sees Notes. Tue interest in the study of navigation by lake sailors is continually increasing. ‘The publishers of ‘A Manual of Navigation for the Lakes,” are receiving orders for the book _ from all sections, including the Coast. Now is the time to study for the coming season. Send your orders to Bissell & Scrivens, Cleveland, O. Senator Cuniom has presented a resolution in Congress in favor of an appropriation for the building of an iron or steel propeller, costing not less than $175,000 fer use on Lake Michigan, to replace the revenue cutter Andrew Johnson, substantially worn out. House Bill 552 asks for pensions to be granted to certain officers and enlisted men of the life say- ing service, A master of a British steamer has been fined $19.20 by the Collector of Customs at Baltimore, Md. for bringing into port 90 bushels of wheat without entering it upon the ship’s mani- fest. How this would apply on the ‘cut throat’? bill of lad- ing in use on the Great Lakes, it is somewhat difficult to see, as hundreds of bushels which would give the lie direct to a manifest are daily entered during the season of navigation. ConaRessMAN STEPHENSON has again introduced a bill for the survey of a canal to connect the waters of Lake Superior with those of Green Bay. The object is to make a passage for lake vessels from Grand Isiand on Lake Superior, to Little Bay de Nocque. The Whitefish river, flowing into Little Bay de Nocque, is only two miles distant, near its upper course, from a stream emptying into Lake Superior, and these rivers could be deepened, it is argued, and connected with great ad- vantage to commerce. The distance thus saved between Mil- waukee or Chicago to Duluth would be something like 270 miles. THE Secretary of the Navy has appointed Commander A. 8. Barker, Naval Constructor J. J. Woodward and Professor Lenox, of the ordnance department, a board to determine the best paint or composition for the protection of ship’s bot- toms against fouling or corrosion. The board is now in ses- sion at the Washington navy yard. It may be noted that ex- periments on the metal entering into the construction of the vessels is not included in the duties of the commission, nor in our mind need they be as they best way out of the dilemma is to discover a modern preventive and this ig what the com- mission has been appointed for rather than to waste years in finding a metal that will not foul or corrode when exposed to the action of salt water in various temperatures, The “Toledo Blade,’’ in a comprehensive and pertinent ed- itorial on the subject of lake levels, asks if the deep water channels will not ruin the lake harbors, and in support of this theory, advances the facts that the uatural bottom elevations now found, at the extremities of the several lakes, are the sur- est safeguards to a continuous mean level. ‘A deeper channel, it is argued would give a greater outflow, thus maintaining the same level, as on leaving evaporation out of the question, itis plain that the amount of water flowing out ofeach lake is ex- actly equal to that flowing in. To deepen the outlet means then that more will be discharged in a given time than flows in; and this in turn means simply that the level of the lake will be low- ered until the outflow is thereby diminished so that it again exactly equals the inflow.” The entire subject is well worthy of the most careful consideration bofore any radical measures are taken which might jeopardize or involve lake transporta- tion in any worse evils than existing ones. Tuern is a weather prophet called Dr. Hall, with a local habitation and a name, in Carbondale, Pa., who appears to be something of a character. At any rate, what he decides may bring some consolation. This is the way he figures it out, “I reckoned we’d have some snug winter weather ‘long about Christmas time, and I begin to see now that the old signs is just as good this year as they was fifty years ago. It worked a little slower than it sometimes does, but it’s gettin’ around all right after all, For two or three weeks I was ready to ’low that I'd got the figgers and the wind and the moon kinder mixed a little, but Isee now that I was right all the time, and the trouble was all with the weather regulator who’d got his time table turned end for end. It’s all right now, and like as not we'll have two months o’good sleighin,’ and just the kind o'winter weather to make things lively. Good for the coal trade? Well, I reckon so, but I don’t believe in meddlin’ with what I don’t understand. My trade isstone cuttin’ and mason " business, and I don’t meddle wih anything else ’cept the ager, malary and weather, and I ken nock ’em every time, sure as you're born.” Ee LAKE SHIPBUILDERS. Our esteemed contemporary the New York Maritime Register points out in its latest issue the following pertinent facts: ‘The Great Lakes and the ocean are no longer wide apart. When it was proposed to send a lake built steamer to the salt sea, the scheme was langhed at. Now lake built steamere are in the ocean trade, Whaleback steamers from the lakes are to be put Pocific Coast trade. A lake built yacht is now at New for a trip around the world. Indeed, as we have rved, it is only a question of time when our lake will be competing with those on the coast for e over sea carrying trade.” * ON LIGHTHOUSE CHARACTERISTICS. On FrAsu Lenrs—When it was determined to choose periods the same, or nearly the same, for neighboring flash lights, it was found necessary to add distinction by color, objectionable as this isif not enforced by necessity. Without greater accuracy than is generally to be found in the time-keeping of flashing lights, even on shore, the distinction between fifteen and twenty sec- onds could scarcely be relied upon as given by the mechanism, and even if given trustworthily by the mechanism, the distinc- tion could only be discovered by the sailor with certainty by the aid of a chronometer, the use of which isout of the ques- tion asa practical means for recognizing a light when seen. To give sufficient distinction between these two lights, therefore, it was found necessary to use color. The insufhciency of the distinction of flashing lights, merely by length of period, had come to be felt so strongly that a very important fresh distinction was introduced in 1875, The great thing, however, is to find how lights may be most surely and inexpensively rendered distinctive, so that no sailor, educated or uneducated, highly intelligent, or only intelligent enough to sail a tramp through gales, snow-storms, and fogs, may know each light as soon as he sees it, without debt or hesitation. This object is fully attained by the triple flashing light, if quick enough. But the lights now in use are too slow to do full advantage to the triple flash system. When one of them is first seen, it is very apt to be confounded with an ordinary ‘‘re- volving light’’—that is, a single-flash flashing light. Even somewhat careful watching—at all events if the weather or the distance from the light be such as to leave any room for doubt, does not always immediately resolve the doubt. The satisfactory distinctions of group flashing lights are ex- hausted in the groups of two or three or four flashes; because to count five or six, or more, would be embarrassing and liable to mistake at sea. It has been proposed to obtain further dis- tinction by using groups of longer and shorter flashes; but there are optical difficultiesin the way of making, with satis- factory economy, groups of long and short flashes, separated by short intervals of darkness in the group, and comparatively long intervals of darkness between successive groups; and con- sidering low very much more useful and satisfactory at sea is a lighthouse showing long light with short intervals of dark- ness than even the quickest of flashing lighta, it does not seem desirable te push the distinctions of flashing lights further than the double, triple and quadruple groups. Experiments alone can answer decisively the question whether, with equal maximum brilliance in each flash, a flash of quarter-second duretion reeurring every two seconds, or one of half second recurring every four seconds, or one of one second recurring every eight seconds is the most easily to be seen at a great distance, or in hazy weather, From physiolog- ical experiments already made, it has been concluded that one tenth of asecond is a long enough time to fully excite the sen- sibility and perceptive power of the eye, and itseems probable that rapidity of recurrence of the contrast between light and darkness will give a positive advantage to the quicker flash in respect to perceptibility, even when the observer knows in what direction to look for the light; and when he does not know in exactly what direction to look, which is the practical case of a sailor at sea trying to pick up a light, shortness of the time of invisibility is of supreme importance. All things con- sidered, it seems most probable that the quarter-second flash recurring every two seconds will be very much more easily and surely picked up practically at sea than a flash of one sec- ond recurring every eight seconds. Before passing from this subject of flashing lights, I may be allowed to say that I first received my impression of the vital im- portance of quickness in a light from a yery practical man— the man who, in 1866, showed us within a quarter cf a mile, in mid-ocean, where to find the cable which had been laid and lost in 1865—Captain Moriarty, R. N. I well remember when on one occasion, either in 1858, or 186, I do not know which, in making the Irish coast in dirty weather, he said: “Those lighthouses should flash out their characters like your electric signals; every lighthouse should flash many times in a minute, showing you which lighthouse it is every time. That long minute of the revolving light has often seemed to me like an age, when I have been auxious to find out where we were in a gale of wind and rain.—(110 BE CONTINUED.) Fixep Licurs—The fixed light has a great advantage in respect to practical usefulness over the flashing light, in being always visible. The superior brillianey produced by optical condensation of the revolving light is, in some respects, dearly bought economy, when the great diminution of usefulness to the sailor, in its comparatively long periods of darkness, is taken into account. ‘Theorists who praise the reyolying light unqualifiedly for its superior penetrative power seem to forget the counterpart in optics to the great principle in dynamics— that which is gained in power is lost in speed; in flashing lights what is gained in brilliancy is lost in time of inv: lity. The painfully anxious scauning of the horizon for a one-min- ute flashing light, is known to everyone who has ever had oc- easion to look for one in practical navigation; and the compar- atiye ease of picking up a fixed light, and keeping sight of it when it is found, in difficult circumstances, is thoroughly appre- ciated at sea by sailors. Still, if the revolving light can be seen at all, whatever be the difficulty in picking it up, and whatever the annoyance of losing sight of it and haying to pick it up again, it has fulfilled the object of « lighthouse. All are agreed in the maxim that ‘the grand requisite of all sea lights is pen- etrative power;”’ and if the fixed light cannot be seen at a dis- tance, or in weather in which the revolying light is seen, the fixed light has failed, and the revolving light has done its work for the occasion. It depends very much on the special circum- staaces whether the eame quantity of light, given out uniformly as a fixed light, or condensed and given out in flashes, with comparatively long intervals of darkness, as in the revolving light, is better in respect to being seen, In stormy or variable weather, with heavy showers of rain or snow, the fixed light is much safer than a one-minute revolving light of much great- er absolute brilliancy; as several successive flashes of the re- volving light may be lost through passing showers, while the fixed light loses no chance of being seen in intervals between the showers. On the other hand, in hazy or fogy weather§ of tolerably steady character, a revolving light can be seen effic- iently at a great distance than the same absolute quantity of light, given out uniformly as a fixed light. The great defect of fixed lights at present is the want of characteristic quality by which the sailor, when he sees a light which really is a lighthouse light, may immediately feel sure that it is so, and not a steamer’s mast-head light, nor a trawl- ers or fishing-boat’s light, nor a light on shore other than a lighthouse light, and that knowing it to be a lighthouse, he may know exactly which of two or more possible lighthouses it is. The need for thorough-goiug remedial measures to remove this defect has been more and more felt of late years, and is now very generally admitted. Unless a second light is to be added, or the generally objectionable expedient of color for distinction is in any particular case to be admitted, the only systematic means of giving characteristic quality to a fixed light is by means of occulations or eclipses; and hence the ori- gin of the ‘‘occulting” or ‘‘eclipsing” light. The important question is now to be met—how may eclipses be best arranged to give the requisite number of characteristic distinctions, for the large number of fixed lights on our coasts whi¢h need distinction, with as little as may be of interference with the valuable quality of fixity? The answer, I believe, is by groups of eclipses described as follows: First—one, two, three, or four very short eclipses, say of not more than one second each, separated by equal intervals of light inthe group, and the groups of eclipses following one another after intervals of not less than eight seconds of undisturbed bright light; next groups of two or three short and long eclipses, the short eclipse one second, the long eclipse three seconds, the interval of light between the eclipses of a group one second, and the interval of undisturbed light between the groups of not less than eight seconds. I fixed upon the time one second, because, after many trials of mechanisms to produce the eclipses, I found that I could produce all the groups of eclipses at the rate cor— responding to one second for the short eclipse by a simple and inexpensive machine applicable to any lighthouse, large or small, and of any variety of optical arrangement, whether merely with condensation to the horizon, or with the additional appliances required to condense into a particular azimuth. coeoror———— A AR FORREST SILVER BRONZE PACKING. N ORDER TO ANSWER ALL THE NUMEROUS EN- quiries as to the price of Forrest’s Silver Bronze Pack- ing and where it can be obtained, we have secured their price list which we publish with the address of the Company for the benefit of our subscribers engaged in mechanical pur- suits. PRICE LIST OF FORREST SILVER BRONZE PACKING, Diameter of; Rais Solid. Sectional. 3in & over! $8 perin| $12 per in 2in to 3 in TO eer ie8 Ta sath ke 1} in to 2 in Dera ROW Mey Ge Lintolpin| 14 « | 18 « « All under one inch reckoned as one inch. Address No. 115 Liberty street, . New York City, U.S. A. This Company has successfully packed thirty-four extensive plants during the last month, among which are the steamers Caribbee, Guyandotte, Maryland and Albany. These boats could not find any other packing to hold their rods tight be- fore. These are only a few of their steamboat jobs, and men tioned because of their heretofore difficult nature. Also the elegant new triple expansion plants of the Edison Electrie Illuminating Co., at 49 West 26th street, New York city, and Paterson, New Jersey, and the Municipal Electrie Light Co. . 310 Penn street, Brooklyn, New York, and several other elec- tric light high speed engines, also the Watts-Campbell engines, at the New York Biscuit Co., 9th avenue and 15th street, New York, a pair of the best Tandem engines in the superb engine room at that address, also the electric light plant of the New York and Brooklyn Bridge. It has supplanted the metallic acking heretofore used by the Social Manufacturing Co., Wea Mills at Woonsocket, R, I. Shipments have been made to Rotterdam, Holland, as well as to many domestic places from Maineto Oregon. Its users are all willing at any gre time to show its excellent performance. Owing to favor with which Forrest’s Silver Bronze Packing is be ceived throughout this country and Europe, it has bec necessary to increase the size of their already large plat now any orders that are sent will be executed will promptness,