issn.j 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



443 



a solid body, it would adviinre the length of its pitch in each levoliition, 

 or 1200 feet per minute, which is the same as IS (i miles an hour; hnt, 

 since the vessel, and consequently also the screw only advanced at the 

 rate of 0.9 miles an hour, (here must have been a recession of the screw 

 through the water, in the direction of the shaft, equal to 3.7 miles an 

 hour. The proportion of the available power of the en^'ines effectively 

 employed in propellinp; tiie vessel was, therefore, 72.7 per cent,, the 

 remaining 27.3 per cent, being expended in obtaining the necessary 

 resistance to the propeller. 



iMr. Herapatli, in his report in the Railway Magazine for the 19th 

 October, has counnitted an error of 1.1 mile an hour to the disadvantage 

 of the perfoimauce, in consequence of taking ihe mean tiuie of running 

 a mile, and findin;; tlie corresponding speed, instead of taking the mean 

 of the speeds with and against the tide. We believe the latter to be the 

 nuuhod usually followed ; but, in case there may be any doubt as to its 

 correctness, it is easily demonstrated thus. 



The speed with the tide is equal to the velocity of the vessel through 

 the water (which is required to be determined), added to the velocity 

 of the tide, which is an indeterminate quantity. Also llie specil a:;ainst 

 the tide is equal to the velocity through the water, diminished by the 

 velocity of the tide. If, therefore, we call the former ( and the latter 

 r, we shall have 



Speed with the tide = V + v 



.Speed against the tide = F — v 



By adding these two quantities together, t; is eliminated, and we find 



that the speed with the tide, added to the speed against the tide, is 



€qual to twice the speed through the water. 



THE HONOURABLE EAST INDIA COMPANY'S STEAM SHIl', 

 THE " QUEEN." 

 The tine vessel, which is of the same class as the government steamers, 

 Medea, I'hcenlx, Salamander, and Rhadamanthus, was built at Lime- 

 liouse by Messrs. Curling and Young, the celebrated builders of the 

 British Queen and President, and fitted with a pair of engines of 110- 

 horse power each, by Messrs. Seaward & Co., of the Canal Iron Works. 

 She is furnished with Hall's patent condensers, with appaiatns for 

 supplying the boilers with distilled water to make good the waste. The 

 slides are ofjlessrs. Seaward's patent. The armament consists of four 

 32-pounders, besides two long guns of 8-inch calibre, one forward and 

 the other aft, inteniled to carry hollow shot ; they move upon slides and 

 tixed pivots, which enables them to take :>. much wider range than the 

 ordinary carriage can give. 



The following are the principal dimensions of her hull and machinery : 



Length between the perpendiculars 173 feet 



Breadth within the paddle boxes 31 „ 



Breadth over all 19 „ 



Depth of hold 19 ft. 6 in. 



Buildei's Tonnage. 



ibl) - tons 



114 



Weight of the hnll .511 



Diameter of the cylinders 5(; inches 



stroke ot the pistons .5 feet 



Diameter of the air pump 28 inches 



Length of Stroke 2 ft. G in. 



Area of the steam passages into the cylinders CO square inches 



Area of the eduction passages 95 „ 



Number of tubes, It long and J inch diameter in 



the two condensers 2.500 „ 



Diameter of paddle wheels 22 feet 



Length of the floats 8 „ 



Depth of the outer boaid 10 inches 



Depth of the inner 12 „ 



Advance of the outer board before Ihe inner one 8 „ 



Number of pairs of floats on each wheel 20 



Number of boilers 2 



Number of furnaces 



Lenglli of boilers 14 fVet 



Breadth of the tsvo boilers 21 ft. ti in. 



Weight of the engines 220 tons 



Weight of the boilers 42 „ 



Weight of the water they contain when filled 30 „ 



Weight of the coal carried 240 ,, 



Which at 10 tons per diem is sufficient for 1.5 days 



On Thursday the 2tth ult. the "Queen," with a parly of naval and 

 scientific gentlemen on board, made an experimental trip from Black- 

 wall down the river as far as Greenhithe. When she was got under weigh, 

 we perceived that the Archimedes, which was lying a little farther down 

 the river, had her steam up, and was ready lor a run. Accordingly, as 

 soon as we were nearly on her quarter, she started, and the two vessels 

 maintained nearly the same relative positions for some lime, until we 

 stopped to take a party on board, when the Archimeiles shot a-head, and 

 as she drew about .5 feet less water than the Qiucn, she was enabled to 

 keep nearer in shore, so as not to feel the full influence of the tide. 

 Notwithstanding this advantage the Arcliimedei did not seem to gain 

 up"n ns, by which we judge her speed ihiuugU the icater to have been 

 rather less, or at least not more than ours. The Archinuda returned 



without having proceeded so far as Erith, or having ascertained her rate 

 through the water; but, by conipaiison with the s|)eed of the Queen, as 

 I'ound at the measured mile in Long reach, we should su|)pose it to have 

 been about 9^ statule miles an hour. As she passed ns on her return 

 she filed a salute of two guns, we suppose in token of victory. We then 

 proceeded to Long leach, wlipre we noled the time of riinniug a mile, 

 first against both wind and tide, then with both in favour. The results 

 were as follows : 



Time of lunning the mile against the tide . 9'3" 

 Time of running the mile with the tide . 4'44" 



whence we deduce llo' speed of Ihe vessel over ihe ground. 



Against the lide G.32 miles. 



With the tide 12.08 „ 



iMean speed, independent of the tide 9.5 „ 



The nnird)er of revolutions of the wheels per minute, vvith wind and 

 tide in favour, was 19j — -against wind and tide, ISJ, which shews that 

 the dift'ereuce of speed through the water must have been more than half 

 a mile an hour. 



The mean draught of water was about 14 fiet C inches, and the dip of 

 the f!o;;ts 3 feet 9 inches ; but, as the ship had a " a list to starboard," 

 the (lip of the hu board wheel was a little less, and that of the starboard 

 wheel a little mure Ihaii the above : which accounts for the fact, that 

 the back-waler from the latter was rather consiileiable while there was 

 nothing but a slii;ht fall of spray from the former, through which the 

 wheel was distinclly seen. 



The piessure in the boiler before the experiment, was 5lbs. on the 

 square inch, but just before we arrived at the measured mile, it had 

 fallen to 4 jibs. The gauge on the starboard condenser marked 

 29 -fif inches of mercury, and that on the larboard condenser 29 [i ; the 

 oscillations were seldom grea-er than y^ of an inch, sometimes even 

 less. The motion of the engines was during the whole trip remarkably 

 smooth and n giilar. 



Having finislied the above experiments, we were siimmoued to an 

 elegant and substaiiti.il cold collation, which had b en prepared by our 

 hospitable entert, liners, the Messis. .Seawaid, and the day passed very 

 ai:retal)ly, in spite of the weather, which was by no means such as to 

 enhance the pleasure of an excursion by water. 



Government Steamer. — Orders have been received .at AVoolwich dockyai'd 

 from the Lords of the Admiralty, to build a steam-ship of 200 horses power, 

 to he named the Lizard. She is to lie constructed with all possible expe- 

 ilition. 



Vernmi Steamer anil Sailiiuj Sliij). — The Vernon is 170 feet long, 30 feet 

 beam, and 22 feet deep, drawing about 15 feet inches water, and of 1000 

 tons measurement. She is fitted with a steam engine of 32 horses power, 

 manufactured by Messrs. Seaward, and calculated to make, in calm weather, 

 30 revolutions in a minute ; the boilers consume about 2^ cwt. of coals per 

 hour. She lately left Blackwall, on a trial against a strong flood tide, with 

 jib and driver set in the wind's eye, blowing very bard from the S.S.W., the 

 engine propelling her at the rate of about 3.V knots the hour, and performing 

 18 revolutions per uiiuute. It apjiears from accounts tliat have been received 

 of the performances of this vessel since her departure, that the propelling 

 apparatus is of considerable service to her as a sailing ship. She is expected 

 to maketlie voyage to India in about 70 days. 



Tin- '■ Allciitlc " SU'im-Sliip. — This fine vessel may no'.v be seen, in all her 

 proporiiuns, in (he Ijuilding-yaril of the Messrs. Wilson, north side of the 

 Clarence l)«ck, Liverpool. She is building for the Transatlantic Steam Com- 

 pany, and intended as a companion to the Liverpool in the Now York trade. 

 Her tonnage exceeds that of the Liverjiool by nearly 500 tons, and slie Hill 

 be ready for launching in the course of six weeks or two months. 



T/ic IVitJiam Commissioners having, from repeated observations satisfied 

 themselves that the great speed and racing of ihe steam-packets on the river 

 are causing much injury to the banks and foreshores, are aljout restraining 

 them to a lesser speed l,i/ lime.~an allernativc to nhich they have bad_re- 

 conrse before. Tlie present packets lieing propelled by engines of from 25 to 

 30 horses power, and being high-pressure, are « orked generally at from 40 to 

 50 lbs. on the square inch ; su'ch vessels mav work with perfect .safety in the 

 large tidal rivers or estuaries of the sea, but are altogether unfit for naviga- 

 tions like the M'itham ; "nd unless some new mode of propelling steamer.s 

 can be adopted which will abate the great agitation of the waters from the 

 old paddle-whiel. the sooner the jwrties liable to uphold the river stop the 

 injury now going on, the better.— .SVnw/on/ Mercnrij. 



Messrs. .Irraman. of nrislol.—'l'bc spirited bouse of the Messrs. Acraman 

 are about to enlarge llic engineering branch ot ibcir trade, already very ex- 

 tensive and of high repule. They liave taken into partnership Thomas Hol- 

 rovd, Esq., late of the lirm of Ferguson, Brothers, and Co., of Calcutta, and 

 William Morgan, Esq.. of London, Engineer ; and the designation of tins imr- 

 ticular department will, in future, be " Acramans, Morgan, and Co." Mr. 

 Morgan is a {lentlemaii of known experience, and under bis able direction the 

 energies of the concern are, we underslanil, about lo be directed to the ma- 

 nufacture, with oilier machinery, of the most powerful engines, as well as for 

 marine as fur rail-road purposes. They have also, we have heard, taken the 

 ground beyond Clift-bouse. directly facing the course of the river, whieli they 

 intend as a yard for the building of iron steam-ships. Emiiloymenl will thus 

 be created fin- a great number of bands. We cordially wish the concern all 

 success. — Bristol Journal. 



