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1902.] MARINE REVIEW. 2i avoidable, and that there are no grounds for drawing therefrom the gen- eral consequences the committee have thought it their duty to deduce. The ships of all classes and all nationalities which navigate on far distant stations, the mail steamers which are daily plying on the South American lines as well as those of Australia and the far east, undoubtedly prove that the tightness of Belleville boilers on the longest runs and the most pro- longed and rapid voyages is a practical and certain fact. Radius of Action--This question of water loss which, in spite of the numerous and well known facts which we have just mentioned, is treated in the report as inherent in this design of boilers, led the committee to conclude that the Hyacinth's radius of action was limited, not by her coal consumption but by her consumption of water. But water loss is an abnormal condition and may be avoided; we have just demonstrated this and there is no need to go over the ground again. Consequently in order to ascertain the true radius of action of the Hyacinth, or of a similar ship fitted with Belleville boilers, it is necessary to cunsider what this radius should be, having regard to the relationship between the amount of coal consumed and the coal capacity of the bunkers, eliminating as far as possible all factors not connected with the boilers, since it is the ques- tion of boilers alone which is here under discussion. But let us take first the bare figures given in the report. The Minerva at 7,000 H.P. ran 2,640 miles and burnt 977 tons of coal (page 17, lines 30 and 31). The Hyacinth ran 1,810 miles and burnt 676 tons of coal (page 16, lines 63 and 49). Such are the material facts. On comparing these figures it will be seen that the Hyacinth by burning the same quantity of coal as the Minerva, namely 977 tons, would have run 1,810x24+¢--2,616 miles. Therefore, comparing the radii of action corresponding to the same amount of coal burnt, the Minerva has an advantage of only 24 miles over the Hyacinth; that is to say, less than one per cent. This difference is almost insignificant in itself, but we shall see that if the two types of boilers had been fitted in conjunction with engines and hulls of the same efficiency all the advantage would then have been with the Hyacinth's boilers and would be proportionately greater. As a matter of fact, it is found that the efficiencies of the engines and hull of the Hyacinth were actually such as to diminish the radius of action of this cruiser in com- parison with that of the Minerva. As far as the main engines are concerned the report shows that the thermal efficiency was greater in the Minerva than in the Hyacinth--16.7 per cent., instead of 15.1 (page 18, line 34). This is a difference of 10 per cent. to the detriment of the Hyacinth, which, all other things being equal, would have had her radius of action increased in the same proportion if the same power had given the ship the same speed. But the influence of the hull here again makes itself felt, for at the same powers the Hyacinth developed less speed than the Minerva; and this difference was very con- siderable. The report (page 18, line 22, etc.) gives the following im- portant information on this subject: "Tn reference to the speed of the two ships, it was seen from the start, both vessels working at the same power, that the Minerva was the faster vessel. This result, however, to whatever cause it may be due, had noth- ing to do with the question under consideration by the committee, and is in accordance with the contractor's trials, of which all the figures (a sum- mary is given below) have been before the admiralty for some time: Hyacinth Minerva Ui. P. Speed (knots.) H. P. Speed (knots). 2,146 12.10 4,919 17.52 7,678 17.34 8,216 19.60 10,447 19.40 9,902 20.34 - "These figures appear to be also in entire agreement, so far as the Hyacinth is concerned, with the results of the special trials of that ship made in Stokes bay in 1900." According to the foregoing extracts from the committee report the Minerva was faster at 4,919 H.P. than the Hyacinth at. 7,678 H.P., 17.52 knots instead of 17.34. Is it not strictly equitable, in order to strike a fair comparison, from the boiler point of view only, that allowances should be made for elements whose influence is so considerable. We do not insist on the fact that the Hyacinth had at her disposal on the run to Gibraltar only 968 tons of coal, while the Minerva had 1,016 tons in her bunkers, i. e., 48 tons or 5 per cent. more (page 15, line 48). If the two ships had been obliged to use all their coal the Minerva's radius of action would then have apparently been increased by 5 per cent., and in fact the Minerva's trial was closed before her coal was exhausted, but after she had already burnt 977 tons, or more coal than the Hyacinth had in her bunkers at the start. The conclusion drawn from the comparison of the radii of action of the two ships was on this account rendered misleading at the outset, for the object of the trial was to compare the powers of the boilers and not the bunker capacities of the two ships. In short, the gross results of the Gibraltar run at 7,000 H.P. make out the Hyacinth's radius of action to be 1 per cent. less than the Minerva's, while if these results are looked at from the boiler point of view only, and allowance is made for the fact that the Belleville boilers were being used with less efficient engines, a slower hull and a smaller bunker capacity, it is found that the advantage is very greatly in their favor. : et Choking of Ferrules of the Minerva's Tubes--The inferiority of the Minerva's boilers from the point of view of radius of action, was not only due to their large coal consumption, in spite of the use of retarders, but also to the gradual choking of the ferrules of the tubes by "bird-nesting, which was in all probability encouraged by retarders being used. Indeed, the committee state (page 17, line 50, etc.) that in order to maintain the 7,000 H.P. on the Minerva it was necessary to gradually increase the air pressure to six times its former amount (1.50 in. instead of 0.25 in.), be- cause of the gradual choking of the ferrules, and even with that during the last seven hours of the trial the power could not be fully maintained. "The openings in the ferrules were found, on examination at Gibraltar, to be choked up across half or three-quarters of their area by a thick hard brown slag, which also coated the surface of the tube plates, and which was not removed until access was gained, after cooling, to the combustion chambers"--(page 18, line 3). This circumstance shortened the duration of the trial, although the Minerva had still 39 tons of coal in her bunkers (page 17, line 58). '(Chokings of a similar nature also wes place on the run home and on arrival at Portsmouth (page 23, line 51) the ferrules in all'the boilers were found partially closed with "bird's-nesting similar to that found 'at Gibraltar, though not so badly, on account of the lesser duration of the run. ee ae committee (page 18, line 15) state their opinion that in practice he obstructions would not have appreciably delayed the ship beyond the time necessary for coaling. We may, however, be permitted to point out that the Minerva (page 19, line 10) arrived at Gibraltar during the night of July 12-13, at 12:30, and that it was not until the forenoon of the 14th (ib. line 18), that is 16-17 hours afterwards, that the boilers were suffi- ciently cool for men to work in the combustion chambers and to com- mence to remove the deposits adhering to the tube plates and ferrules. The time spent on cleaning these parts is not stated, but considering the adhesive nature of the deposits and the fact that they were not confined to the ferrules, but extended over the whole surface of the tube plates (page 18, line 5), the total time occupied in cooling the boilers and in cleaning was certainly much greater than that to which, in case of neces- sity, a ship of war can reduce the time required for coaling. In short, the obstructions were, after only 150 hours steaming, sufficiently serious to prevent the power from being maintained, and to necessitate the aban- donment of the trial while the ship still had coal available in her bunkers. These facts bring to light a serious fault as regards the Minerva, for in practice ships of war or commerce have frequently to make runs of much longer duration than 150 hours. Circulation and Water Levels--During the run home from Gibraltar a tube burst in one of the eighteen boilers of the Hyacinth. The report, in touching on this, reiterates the apprehensions and criticisms already formulated in the interim report of Feb. 19, 1901, on the untrustworthi- ness of the water gauge indications and the defective circulation which, in the opinion of the committee, are the characteristic features of Belle- ville boilers. For our part, we can only repeat the observations on these points we had the honor of laying before the admiralty in our letter of March 28, 1901. The fact that a tube burst during the trial in question cannot nullify the results obtained every day with the innumerable Belle- ville boilers which are in use on every sea, beneath the flags of all mari- time nations. After all, there is no type of water-tube or cylindrical boiler in existence which, having been in use to any considerable extent and for any length of time, has not occasionally met with accidents to its tubes similar to that which happened in the Hyacinth. The coming down of furnace crowns in cylindrical boilers is far from being an infrequent occurrence, and the consequences are generally very serious indeed. There are, therefore, no grounds for drawing conclusions adverse to the Belle- ville type alone from an accident to which all types of boilers are ex- posed. The diversity of uses to which this boiler can be put, its well established position, and extensive use present, on the contrary, guaran- tees that few other designs can offer to the same degree. Weight and Space--The report (page 14, line 3, etc.) states that: "The net space occupied by the main and auxiliary engines and evap- orating plant in the Hyacinth is 28,200 cu. ft. (798.5 cu. metres), and in the Minerva 29,240 cu, ft. (828 cu. metres). Taking these figures in con- nection with the maximum horse power measured on any of the com- mittee's trials over a period of several hours (10,180 and 8,657 H.P. re- spectively) they amount to 2.8 and 3.4 cu. ft. (79 cu. decim. and 96 cu. decim.) in the Hyacinth and Minerva respectively. The weight of the boilers with funnels and water, and the whole of the boiler room weights generally, are 453.8 and 557.4 tons in the Hyacinth and Minerva respec- tively. Worked out on the same horse power as in the last paragraph, the figures come to 22.4 and 15.5 H.P. per ton of boiler weights." The difference in weight for the complete groups of boilers is there- fore 103.6 tons, i, e., the Minerva's boilers weigh 22.8 per cent. more than those of the Hyacinth, and comparing the maxima powers realizable per ton of boiler weight it is seen that the Hyacinth's boilers can develop 44 per cent. more power than the Minerva's. These differences are con- siderable. The committee is of opinion that this advantage is illusory, and that the economies realized may be more than counterbalanced by additional weight of coal and water necessary (page 14, line 18). .But we have already pointed out that difficulties in regard to loss of water have arisen in no other navy, nor has it been considered necessary to provide for greater water reserves for Belleville boilers than for any other type. We have likewise shown that, according to these very results obtained by the committee, Belleville boilers possess incontestable advantages from the point of view of efficiency, and cannot therefore themselves be the cause for increasing the coal supply. The important economies of weight and space shown by them stand to their credit, therefore, as an incontesta- ble advantage. In conclusion, we beg to be allowed to point out that since the pre- liminary report of the committee was published in February, 1901, a whole year has elapsed, during which time, taking the British navy alone, about fifteen large ships fitted with Belleville boilers have been added to the service, and twenty others have been kept in commissiun in distant seas or in active squadrons. The increasing use of these boilers appears to us not to confirm the fears of the committee, but, on the contrary, to show that in the British fleet, as in all others, these boilers daily justify more and more the confidence reposed in them. And, to mention only the ear- lier cases in which these boilers have been fitted by the admiralty, the cruises of the Powerful and the trials carried out some months back by the Terrible have shown that Belleville boilers, after six years of use on board, and after long cruises in distant seas, are always capable of render- ing the best and most reliable service, and: have lost nothing of their power and usefulness. ~ In connection with the Olympian games scheduled for Chicago in the fall of 1904 it has been suggested that a naval pageant be held, the purpose being to demonstrate that the lakes are capable of being navigated by ocean-going craft. This sounds bigger than it really is. The vessels which could reach Chicago from the ocean in 1904 would be limited in size to the dimensions of locks in the Canadian canals. The average length of a Canadian canal steamer is 250 ft., the canal not permitting the passage of a steamer of greater beam than 43 ft., and length must always bear a certain ratio to beam. The tendency of the ocean carrier is to greater and greater draught; and therefore the lakes will never be seaports in a cotimercial sense until the St. Lawrence river canals have far greater dimensions than they have at present. The pageant would be interesting and 'éntertaifin& but not valuable. My 910 LY a this The new issue of Dominion Iron & Steel Co.'s'stock has all been underwritten.