lamps supplied to the Admiralty were guaranteed to act for eighteen consecutive hours, and to be watertight; that is to say, even if they played with a hose, of two or three inches diameter, upon the lamp the whole day they would not force a drop of water into the flame. I have not seen the reports made upon the lamps, but the Admiralty has ordered a much larger quantity of them, and has paid for those previously had. I think that is sufficient evidence that they are satisfied.

I feel very much gratified at Captain Colomb's remarks. Criticism on the part of Captain Colomb I look upon as a compliment, for I do not think there is another gentleman who has studied the question of lights for ships so much as he has. But I believe be is to some extent under an erroneous impression in saying that all my lamps must have an increased size. To some extent he is right, because the larger the flame the greater must be the circumference of the lamp. Of course in a room where one person could live comfortably, fifty people could not breathe. Some of my lamps, therefore, are larger in proportion according to the light. Now, as to the trimming, the question is this: to fit the lamps to the men, as Captain Colomb has rightly expressed it, therefore I have provided a wick of a certain size cut by machinery, perfectly level and perfectly smooth; and there is this fact, that if the wicks have a quarter of an inch cut out of four different places, the combustion with the wick so deranged is equal to what it would have been if the wicks were perfect. It would make no difference whatever.

Captain Colomb also alluded to a distance of five miles; that is the regulation distance for mast-head lights. I consulted Professor Tyndall on the subject, and he said, "I am perfectly satisfied with what you have done; continue in the same direc "tion." I have also heard an objection raised, which has not been raised this evening, that it might be mistaken for a lighthouse; but Professor Tyndall said he was not at all frightened at that, and besides, with the arrangements they are making at the present moment for lighthouses, the lighthouse can be very easily distinguished from a ship.

The peculiar green of the lens of this starboard lamp is a very important matter. These lamps were tried at a competition at Shoeburyness, and I have a certificate in my hand which states-"One point, visible, bright; two, visible, bright; three, not "quite so distinct; four, ditto; five, clearly visible; six, ditto; seven, bright; eight, ditto;" one point above being not so distinct, and two points ditto. "As to "that showing more ahead than ten points, no." Of course that is satisfactory, so that this passed Shoeburyness as being a perfect lamp.

I was asked whether I had recently seen the lighting in ships. I asked permission of the Admiralty, and went recently on board H.M.S. "Thunderer," and also on the "Minotaur;" and, as I stated in my paper, I found that a dip light, certainly not thicker than my little finger, was fixed against the wall with a small piece of tin, and twelve men were sitting round the table, of whom eleven could not do anything, and the twelfth man was attempting to mend some article of clothing.

On the question of suspension I may say that the lamp balances itself; it is carefully calculated as to that.

Captain COLOMB: I meant you must connect your flashing arrangement through your point of suspension.

Mr. SILBER: That is a question of very great importance. I intended to do it by a bell-crank arrangement, to be so adjusted for on signalling with the aid of cords as to make its action as simple as that of Captain Colomb's. I am not satisfied with the results in my own mind. It seems to me, at present, that the disadvantages so counterbalance the advantages that perhaps it may be quite as well let alone.

Captain COLOMB: You cannot use your lamp for flashing purposes unless you have that, because the slightest motion of the lamp will cause the shades to open.1

1 Mr. Silber did not understand Captain Colomb to have made this last remark. or he would have replied that on the contrary no violent motion, no vibration of any kind, not even that produced by the discharge of guns on board, would cause the shutters to open, as they are locked by a rack and pinion as well as a screw bolt. On the last occasion of Mr. Silber's visit to H.M.S. "Minotaur," Lieutenant Campbell, R.N., kindly showed him all the positions in which signal lamps used, and Mr. Silber has provided for his signal lamp being used in all similar positions.

The CHAIRMAN: I think we may now bring our proceedings to a close. Before doing so I wish to make one remark upon an observation that fell from Captain Colomb. He alluded to what he called the complications of Mr. Silber's lamps being too great for the men who would have to use them. Now I think, considering the state of complication of all our new ships, filled as they are with machines of all sorts, the great guns, as we heard here the other afternoon, worked by very complicated machinery, I think if the men are intelligent enough to be brought up to use all these machines, we need not despair of Mr. Silber's simple arrangements being used with intelligence. And I think my friend, Captain Colomb, rather contradicted himself, for in arguing with regard to the Morse signals he said there was no difficulty whatever. Now, I think, if a man can master the Morse signals he may very easily master the arrangement of Mr. Silber's lamps. I am sure we are all highly indebted to Mr. Silber for what he has brought before us. I certainly had no idea that there was so much to learn and so much to see with regard to these lights. The old "dip"-Mr. Silber called it a "rushlight "--is an old light we knew very well at sea. When I was on service formerly, I always felt that the way the lower and orlop decks and the interior of our ships were lighted was a perfect disgrace—it was quite lamentable to go down below in those ships and see the miserable horn lanterns we had to carry about, and the indifferent lighting where the men lived. I believe it is better now; at any rate, if not, it ought to be. I maintain that every ship ought to be as light_below during the night as if it were daylight. With these observations I am sure I am only doing my duty, as Chairman, in conveying to Mr. Silber our heartfelt thanks for the paper he has read to us.

Evening Meeting.

Monday, April 15th, 1878.

ADMIRAL SIR FREDERICK W. E. NICOLSON, BART., C.B., VicePresident, in the Chair.

STEAM-POWER VERSUS SAIL-POWER FOR MEN-OF-WAR. By Captain P. H. COLOMB, R.N.

1. In my Essay on the "Development of our Maritime Power," I have rested the propulsive force of our war ships almost entirely on their coal stowage, and on the means at disposal for their replenishment with coal in our own depôts. I have proposed that the sail-power of our war ships should be reduced to the position of a true auxiliary. We should, I have assumed, build our war ships without any reference whatever to sail-power; and after the design is completed, we should then furnish them with such a rig as should give them the least possible inconvenience in foul winds, and the greatest possible assistance in fair winds.

2. So bold a proposal requires some facts and arguments to back it, and I am here to-night to offer both for discussion.

3. Though a considerable change has passed over our minds within the last ten years in the view we have taken of the relative position of steam and sail power in a war ship, I am not without apprehensions of being considered rather too advanced in my present views. But I trust that those of my brother Officers who start at what may seem at first revolutionary theories, will understand that I do not advocate any sweeping changes without due experiment; and that I do not think we can advance at all, unless we do so on certain ground.

4. On the other hand, I have reason to believe that I should now carry with me a considerable body of steadily-formed opinions, were I to confine my views of the decadence of sail-power to the ironclad-or as I hope she may in future be called, to the Fleet Ship. I have been a little surprised to find what an alteration naval opinion has undergone in this matter even since I left England in 1874. These things make me hopeful that, though I may be too advanced at this moment, I shall be perhaps behind the age in five years' time.

5. But, in any case, whether I be too advanced, or altogether mistaken, in the views I put forward, there is great value in advancing them. I do not know any method of examining the soundness of old views better than testing their strength by the advancement of new ones. And, while I would always deprecate the ventilation of ideas which are simply wild, and rest on no definite data, I am a great advocate for the publication of all views which have such a foundation,

cven though the conclusions drawn may turn out to be wrong. I have, in short, a great faith in the accumulation of FACTS as a basis for argument, and believe that such accumulation is never made in vain.

6. The method I have adopted in this accumulation of facts may, I think, be relied on so far as it goes. It has involved some patient labour, but promises the advantage of being truly inductive, so that the facts established form a perfectly solid basis, whether the conclusions to which I think they point may or may not be approved,

7. Serving recently in an ironclad, I very early became impressed with the smallness of the results due to the employment of her square sails, but I was not at first prepared for the insignificant appearance their propulsive power would exhibit when investigated and compared with that of the engines; and most certainly I was not prepared to accept my present conclusions, which I may state were adopted by Captain Fisher as far back as 1871.

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He then wrote:-" Masts and sails should be done away with. The weight and room they now represent should be taken by coal. No "better proof exists of the wisdom (the economy and efficiency) of doing this, than pointing to the example of all the new ocean steamers, amongst the most successful of which are Mr. Holt's. These steamers, "built more for cargo than speed, make the passage from Liverpool to "Singapore in 45 days, and they carry 90 days' coal. A paper might "be written to prove the actual waste of coal caused by masts and "sails in squadron sailing, due to the frequent stoppages and altera"tions in speed; and it may almost be asserted, as a general rule, "that the cost of refitting exceeds the value of the coals, which would "have been used in the year's cruize had steam alone been used."

8. I have, in fact, made a long series of the calculations imagined by Captain Fisher, and the results are, to my mind, nothing less than startling in their confirmation of his views.

9. But, for investigations of this sort, the experience of the Channel and Detached Squadrons must generally prove exceedingly misleading, for their proceedings and movements are usually governed by their interior convenience, and not by the pressure of circumstances outside them. The test which is required to finally establish the proportions of sail and steam power proper to a modern fighting ship, is that of war; but very often the ordinary service of a foreign station so closely resembles a state of war, that useful conclusions may be arrived at, even in peace time. When the movements of a ship are governed by circumstances outside herself; when she must be at certain places at certain times without any reference to her interior convenience; the real value of her propulsive powers becomes apparent, and she establishes facts relating thereto, which, if carefully investigated and recorded, become an excellent and reliable guide for the future. A Fleet Ship on a distant station, with a good deal of sea work, and almost always impelled from point to point by considerations which, if less imperious than those developed by war, still in some degree represent its demands, appears calculated to furnish seme of the most useful experimental data available in peace time.

10. In order to get at some definite results, I determined to investigate very closely the value of the sail-power of such a ship during a period long enough to make a fair average. I selected two complete years, ending on the 28th October, 1876.

11. The questions to which I have endeavoured, by an appeal to the actual facts, to get answers, are the following:

(a.) The hull, engines, and boilers of the ship being considered fixed quantities, the variable elements of her propulsive power are the coal supply and the masts and sails. The masts, yards, and sails, actually in use, represent a certain weight, and they also induce further weight in the shape of stores; and in the ship in question, a very large additional weight in the form of ballast. Do the sails in their propulsive power represent the equivalent of the weight they involve?

(b.) If it appears that they represent a power in excess of this weight in the form of increased speed, or decreased coal consumption, then it is clear that sail-power is properly arranged. But if it is found that even in peace time, and in ordinary service, the propulsion extracted from sail-power does not reach the equivalent of its weight, it would appear that a re-distribution is required.

(c.) If the sails upon the whole make a loss, instead of a gain, in propulsion, should we not look to their inconvenience to a fighting ship in time of action, and also to the increased draught of water of the ship?

(d.) Taking the lowest view of the question, that of simple saving of money, and supposing still that sail-power as arranged shows a loss stated, say in tons of coal, will not the debit side of the account be very much increased by the cost of wear and tear, and by the interest on capital sunk in the rig?

(e.) If we decided that in any particular ship the existing rig showed a loss, is there any modification of that rig which would give us the maximum of assistance when the wind was fair, with a minimum of retardation when it was foul?

12. It was some time before I succeeded in establishing satisfactory rules for calculating the value of sail-power, but I think those which I finally adopted may be applied to any ship with confidence. The rules are simple, and the process of calculation, though laborious and troublesome, is not difficult, and does not involve any abstruse problems.

13. Table I is one of forty-five which were completed for the purposes of this paper, and its construction may be now described.

(a.) The distances through the water as logged hourly are taken out and totalled, the totals being placed in the columns for distances under steam alone, steam and sail, and sail alone, opposite the number of hours occupied in passing over each distance.

(b.) The coal burnt while actually steaming is placed opposite each distance run under steam alone, and under steam and sail.

(c.) The coal expended in banking fires and waiting orders is omitted from this column, so that when the ship is under sail alone this column is blank opposite that distance.

(d.) The coal saved or lost, and the miles gained or lost by the use of square sails, are calculated in this manner. The best data which