1843.J 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



270 



end of the lever, which traversed the pendant, had become magnetic, and 

 thus atl'ected the balance. An ivory end was substituted, and ever since 

 that period its accuracy had been maintained. 



Mr. W. Miller observed, that the efficiency of any scales must be deter- 

 mined, in a great degree, by the fineness of the edge of the fulcrum of the 

 beam ; and it would be easily imagined that the friction, to which the edge 

 in a pair of bullion scales was'subjected whilst weighing five or six thousand 

 sovereigns per day, must soon impair its delicacy, and consequently the effi- 

 ciency of the whole apparatus : for, whether the sovereigns were light or 

 heavy, the beam must turn upon its fulcrum. Such was not the case with 

 Mr. Cotton's machine: its beam did not act at all, unless a light sovereign 

 was placed upon the platform; so that among 1000 sovereigns, if only 100 

 were light, the beam of (lie machine would only move 100 times, while that 

 of the ordinary scales would oscillate 100 times. An immense advantage 

 was thus given to the machine in point of durability. All weighing was but 

 an approach to correctness, and the nearest point to which the best kind of 

 common scales were sensible, might be stated as -^ of a grain, and one- 

 fourth of a grain would hardly cover their errors ; but the machine was 

 sensible to 6 s aa of a grain, and -^ would fully cover its errors, which were 

 not a twentieth part so numerous as those of the scales. 



Woollen Factory for Turkey. 



Mr. Fairbairn exhibited a model, showing the plans, sections, and archi- 

 tectural elevation of a Woollen Factory, to be constructed of cast and 

 wrought iron, near the town of Izmet (Turkey), for the Sublime Porte. 



Mr. Fairbairn said that, in 1839, he visited Constantinople under the in- 

 structions of the late Sultan Mahomed, and reported upon nearly all the 

 government works. Their extension was checked by the death of that 

 prince, but the present Sultan was disposed to carry them into effect, and 

 by his orders Mr. Ohanes Dadian had arrived in England, in furtherance 

 of the plans for ameliorating the state of the Turkish community by intro- 

 ducing useful arts and manufactures, in which he was aided by his Excel- 

 lency Ali Effendi, the ambassador to the court of England, and the consul- 

 general, Mr. Edward Zohrab. Almost all the houses, and many of the 

 public buildings, in Turkey, being constructed of timber, destructive 

 fires were frequent. In many parts of the country the common building 

 materials were expensive ; iron had therefore been resorted to for construc- 

 tion, and Mr. Fairbairn had already sent over an iron house for a corn-mill, 

 50 feet long, 25 feet wide, of three stories in height, and with an iron roof. 

 It was finished in 1840, and erected at Constantinople in the succeeding 

 year. The success of this attempt induced a second order, which was for 

 an extensive woollen factory, to be composed entirely of cast iron plates, 

 the interior being formed throughout of brick arches, upon cast-iron columns 

 and bearers, with an iron roof. He then described in detail the construction 

 of the different parts of the building, and the machinery, which would be 

 driven by a fall of water of 25 feet in height, of the computed average 

 power of 180 horses. Several ingenious devices were described for pre- 

 venting any objectionable effects from the high conducting power of the 

 metal. The piers between the windows were hollow, so as to admit a cur- 

 rent of air through during the hot season ; and the iron roofs were so ar- 

 ranged as to have beneath them a coating of plaster, to serve as a non-con- 

 ducting substance. The two principal rooms were described to be 272 feet 

 long, 40 feet wide, and 20 feet high ; and 280 feet long, 20 feet wide, and 

 20 feet high : with a great number of other rooms, for the several pro- 

 cesses in the manufacture of coarse woollen cloths, for the counting-houses 

 and departments of the directors, and for the reception of the sultan, &e. 

 The area of the inclosed surface, including the court-yard and buildings, was 

 nearly 3 acres, or 110,621 square feet. 



The floor surface in the basement rooms = 16,480 square feet. Ditto in 

 the upper rooms = 54,616 square feet. 



March 28. — The Presidekt in the Chair. 

 Cast and Malleable Iron. 



" Experiment!: upon Cast and Malleable Iron, at the Milton Iron Works, 

 Yorkshire, in February, 1843." By David Mushet, Assoc. Inst. C. E. 



The blast furnaces at Milton had been for a long period worked with 

 heated air, generally under a pressure of 3 lb. per square inch, and each with 

 two nozzles on the blast-pipes of 2\ inches and 2-^ inches in diameter. 

 The apparatus requiring to be renewed, a quantity of iron was made by 

 cold-blast, which, as the materials or other circumstances of manufacture 

 were not in any way changed, offered an opportunity of testing the relative 

 strength of the two 6orts of iron, of which Messrs. Graham and Co., the 

 proprietors, took advantage, and secured the assistance of Mr. Mushet to 

 conduct the experiments. A strong wooden frame was erected, upon which 

 were fixed iron supports at 4 feet 6 inches apart, for sustaining the bars to 

 be proved. A bar of iron planed perfectly true, with a dove-tailed groove 

 and a graduated brass scale in it, was used for ascertaining the deflection. 

 The bars to be experimented upon were all cast alike, 5 feet long and 1 inch 

 square, and cooled with equal precaution. The results are given iu a series 

 of tables, of which the following are the average results : — 



The result of these tables are examined, and among the deductions 

 drawn from them are — that the Milton cold-blast iron is rather deficient in 

 strength ; that the hot-blast iron is stronger than cold-blast, when re-melted 

 in a cupola with coke ; that hot-blast iron from the furnace is equal in 

 strength to the average of the two sets of specimens of cold-blast re-melted 

 in the cupola; that the No. 3 iron from the blast furnace is not stronger 

 than No. 1 quality. The general results show, not only the superiority of 

 the Milton hot-blast iron over that made by cold-blast, at the same furnaces, 

 but over that of a very large number of works, as shown by the following 

 comparative table taken from Mr. Fairbairn's report in 1838 : — 



lb. 

 No. 3 

 „ 3 



Milton, hot-blast iron, 

 Ditto, hot-blast 

 Ponkey, cold-blast 



Bute, ditto 



Windmill End, ditto 



Air furnace 

 Cupola 



610} 



520 



581 



491 



489 



485| 



472 



463 



459 



455 



449 



448 



448 



447 



4384 



427 



The waste in re-melting the hot-blast iron was under 2 per cent. 



There was charged in the cupola, No. 3, pig-iron 

 Pigs and scraps obtained .... 



Cwt. qrs. lb. 

 20 1 

 19 3 14 



The results of the experiments upon malleable iron made from hot-blast 

 pig, and plate, show extreme ductility, when subjected to blows of a ham- 

 mer 24 lb. weight, of which one example will suffice. A bolt 2} inches di- 

 ameter, puddled from refined metal, notched half round to the depth of 

 one-eighth of an inch, required 120 blows to break it. 



Remarks. — Mr. Cottam remarked, that the paper would have been more 

 satisfactory, if it had stated more particularly the progressive additions of 

 the weights, the intervals of loading, and the length of the periods during 

 which the bars remained loaded. He had found that when a beam was near 

 the point of fracture, if the weights were added quickly, it would apparently 

 bear more, than if a certain time was suffered to elapse between their appli- 

 cation. His practice in experimenting was to make small additions of 

 weight, at given intervals, which might be increased in length toward the 

 point of fracture; more correct results were thus obtained. 



Mr. Lowe believed, that in making iron, the main consideration after se- 

 lecting good materials, was to proportion them according to the hygrometiic 

 state of the atmosphere. It was well known that better iron was made in 

 frosty weather than in damp warm weather; and he was convinced that the 

 more air was deprived of its moisture, the better would be the effect. 



Mr. Paikes observed, that the experiments on the strength of the wrought- 

 iron bars could scarcely be received as conclusive, as the power employed 

 had been variable and ill-defined. If a given weight had beeu allowed to 

 drop from a certain height, and the incisions in the bars had beeu made with 



38 



