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time after it has left the funnels, etc. At night and during fog this cannot be done, so recourse must be had to other methods. There will apparently be a calm on board a steamer going 12 miles an hour when the wind is really blowing with a force of 12 miles from right aft, and on the other hand the wind will blow with an apparent force of 24 miles an hour from dead ahead on board a steamer going 12 miles an hour, when its true force is only 12 miles from dead ahead. When the apparent direction of the wind is at an angle with the vessel's course the true direction and velocity can be determined from that angle and the velocity of the wind and the speed of. the vessel. This may be demon- strated by the parallelogram of forces as in the diagram. In the diagram following let AB represent the course and speed of a vessel in miles per hour and CA the apparent direction and velocity of the wind in miles per hour, as shown by a vane on board the vessel; then con- necting B and C and completing the parallelogram ABCD, the. line DA will represent the true or actual di- rection of the wind and the velocity in miles per hour. Supposing a vessel steaming along AB, or west 12 miles an hour, having the wind apparently along CA, or from the NW 14 miles an hour; then the line DA must have the direction of about one point abaft the beam, its proportional length must be 9.8, or nearly 10 miles. Therefore the true direction of the wind in this case is about 'N by- E, and its true velocity nearly 10 miles an hour. A scale. of centimeters makes a most convenient scale for laying off the distances in this kind of work. Tet each centimeter stand for a mile. It is. convenient because it gives a fair working size to the diagrams. It is likewise convenient because the centimeter is divided into tenths. In the foregoing diagrams each mile rep- resents a centimeter, or the centime- ter is taken as the unit. It is well to know that the true direction of the wind is always fur- ther from the bow than the apparent direction. The true force of the wind is greater. than the apparent so long as the apparent direction is aft of the beam. The true force of the wind is less than the apparent as long as the true direction is forward of the beam. There are a great many other appli- cations of the parallelogram of forces that might be mentioned in connec- tion with these. There is scarcely a limit to the application of this im- "TAE Marine: REVIEW portant principle in the science of forces. « It\:comes: into « play «in a marked manner in determining the weight of span rigged between masts, etc., will sustain. We will give some examples of these another time. This subject is not only a very useful one, but a simple one as well, and as it is not beyond the reach of those who try, one should not be satisfied with himself until he knows all about it. QUESTIONS FOR MASTERS AND MATES.--No. 28. 415. If the deviation is Ely on north, what will it be on south? 416. What is meant by natural devia- tion? 417. What is residual deviation? 418. Your boat heads correct magnetic NE, your compass says NE%N, how much and which way is the deviation? 419. Your boat is heading West cor- rect magnetic, your compass says W by S; how much and which way is the deviation? 420. If the natural deviation on West is Wly, what will it be on East? 421. With a compass having natural deviations (compass unadjusted) it is necessary to steer NNW to make good a course.of North, what would you steer in order to make good a South course, presupposing that the deviation is of the same amount on south as on north? 422. State briefly the essential parts of a good reliable working compass. 423. How could you tell which was the north and south end of a megnet. 424. How could you tell an efficient compass? 425. If you were to test the efficiency of a compass would you do it on. board your ship or on shore? 426. Why is it that no two uncompen- sated compasses on board do not show the same heading of the ship? 427. Is it necessary to have com- passes adjusted? 428. Name some of the advantages of an adjusted compass over one uncom- pensated. 429. What is meant by transient in- duced magnetism? QUESTIONS FOR WHEELSMEN AND WATCHMEN.--No. 29. 291. Explain how you would pilot a boat from one mile south of Portage entry to Princess Point, Portage river. 292. Explain how you would pilot a boat from Princess Point, Portage river, to Houghton and Hancock bridge _ 293. Explain how you would pilot a boat from Houghton and Hancock aon to Lilly Pond. 294. On what -- would you eave « 33 ranges 2 and 3 in passing up Portage river? 295. If you were piloting a steamer up Portage. river, what order would you give wheelsmen when you came to Prin- cess Point? 296. What is the general appearance of the land on both sides of the river from Portage entry to Portage lake? 297. What are the correct magnetic bearings of Portage river runges 14 and 15? 298. With stern of your boat on Port- age river ranges 14 and 15, your steer- ing compass reads N x W14W, how much would it be out on those ranges and which way? ' 299. What signal do you give if you wish to pass through Houghton and Han- cock bridge? 300. On what hand do you leave Os-° ceola Point bound up Portage lake? 301. On what hand would you leave Harrington Isle passing up Portage lake? 302. Give general appearance of land around High 'Point, Portage lake. BATTLESHIPS AND ARMOR. Following the action of President Roosevelt in making a personal appeal for the construction of at least two mon- ster battleships, in line with the policy of Great Britain, there has been wide discussion of the question. Edwin S. Cramp, vice president of William Cramp & Sons' Ship & Engine Building Co., Philadelphia, is quoted as follows: "As a general proposition there is lit- tle doubt that the policy of the American navy will tend in the direction of smaller fleets of larger vessels. England has set the example, and the other countries are following. The policy is a good one, in my opinion. Five large battleships mak- ing up a squadron, each with eight large guns, will prove much more effective, as a fighting unit, than ten ships with four guns each. Not only will the fleets take up smaller space, but they will be more easily maneuvered, which, of course, will be a great advantage." Before the house committee on naval affairs, Secretary Bonaparte explained the recent division of armor plate awards among the Bethlehem, Carnegie and Mid- vale Steel companies, half going to the last named company, which was the low- est bidder. The idea of this division, he stated, was to make clear the stand of the department that "it would act on the principle of getting the armor at the lowest possible rate for the government, with due regard to the possible future exigencies of the occasion." Mr. Bona--- parte was unable to state just what process is now being used in the 'manu- facture of armor plate.