21 1 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[July, 



Tnxh Wants atul Pr/wfical Rnnedien; nn Investigation on Practical 

 and Ei-nuimical Grounds, ns to the Application of a Gorernmcnt System 

 of liailirai/s in Ireland. By Humphkey Brown, Esq., M.P. Lon- 

 don: Burnett, 1848. 



Many of our readers will care very little about a system of rail- 

 ways for Ireland, thouf,'h this little work deserves attention for 

 what it says on that subject; but it requires notice as being the only 

 attempt yet made to apply statistically to a cfiven case the doctrine 

 that railways can be made by means of existing resources, and that 

 they are of'a reproductive character. An additional value is given 

 to it, that it contains the latest statistics on railway subjects, aud 

 many novel ajiplications of them. 



Among the chief points discussed, are the number of persons 

 temporarily employed and permanently employed ; the saving and 

 reiiroduction on agricultural resources ; the effect of extending the 

 area of supply by extending the radius of communication ; the 

 average contribution and mileage of each bead of traffic ; the 

 pecuniary or cajiital resources of Ireland ; the correspondence be- 

 tween traffic estimates aud traffic returns; and the existing traffic 

 on Irish lines of road. 



The following is a curious illustration of railway economics, and 

 supplies evidence on a question which has been often mooted : — 



" Mr. Porter, ill the new edition of his work on the Progress of the 

 Nation, p. 30, has given a table of the estimate of traffic given to parlia- 

 ment by several railways, and by appending to tliem the actual traffic from 

 the returns made in 1845, we shall be able to see how far the estimates 

 have been borne out. 



The estimates for the railways constitutiog the Midland Railway, are as 

 follows : — 



Birmingham and Derby 

 North Midland 

 Midland Counties 



Passengers. 



145,747 

 149,812 

 255,424 



Cattle. 

 7254 



Merchandise 

 Slieep. by Land. 



Tods. 

 27,105 14,547 



— 124,350 



— 12,948 



Coals 



by Water 



Tons. 



285,000 



Total estimated 550,985 7254 27,105 151,855 285,600 



Midland liailway, 1845 1,809,145 30,000 120,000 371,154 313,854 



The Midland Railway traffic included, likewise, 30,000 pigs, and £0,290 

 tons of lime. The merchandise carried by water was estimated at 

 255,738 tons, and this, and a great quantity of coals, are still carried by 

 ■water, so that the railway has, as it were, created an amount of traffic. 



The estimates and returns for the Manchester and Leeds Railway stand 

 thus : — 



Thug the traffic on the railway is greater than all that previously moving 

 by land and water, although the canal traffic is as great as before. 



The estimates and returns of the York aud North Midland Railway 

 stand thus : — 



Merchandise Merchandise Coal 

 Passengers, by Land, by Water, by Water. Cattle. Sheep. 



Tons. Tons. Tons. 



Estimates 185,060 5547 95,100 98,000 63,000 110,600 



Returns 401,755 351,022 — — 15,364 87,039 



The traffic in this case resembles that of the Manchester and Leeds in 

 its results. 



The following are the estimates and returns of various other rail- 

 ways: — 



London and Brighton 

 South Eastern (1847) 



Great North of England 



Great AVestern and Bristol 

 and Exeter (1847) 



Lancaster and Preston 

 Glasgow and Ayr 



Estimates 

 Returns 

 Estimates 

 Returns 

 ( Estimates 

 ( Returns 

 S Estimates 

 \ Returns 

 i Estimates 

 ( Returns 

 \ Estimates 

 i Returjio 



Passengerfl, 



220,444 

 788,380 

 317,252 



1,477,892 



75,158 



190,722 



821,145 



3,876,222 

 100,957 

 135,344 

 597,470 

 831,078 



Merchandise. 



by Land. 



Tons. 



43,705 



65,747 



63,079 



204,100 



32,136 



234,198 



150,710 



371,326 



26,099 

 121,027 

 108,370 



on account of 



This will be found useful as a book of reference, 

 the facts and figures it contains, and the mode in which they are 

 applied, as it is the only work which has yet embraced the subject 

 of railway traffic in a practical and comprehensive manner. 



REGISTER OF NEVtT PATENTS. 



REDUCTION OF COPPER ORES. 



Charles Low, of Roseberry-place, Dalston, Middlesex, gentle- 

 man, for " Improvements in the manufacture of xinc, cnpjier, iin^ and 

 other metals." — Granted November 4, 1847 ; Enrolled May 4, 1848 



The title of this patent is more comprehensive than the specifi- 

 cation, as the patentee disclaims all parts of the title, excepting 

 that relating to copper. The object of the improvements is to 

 quicken the manufacture of copper from its ores, and to diminish 

 the loss of metal. In reducing the ores a compound is employed, 

 consistingof oxide of manganese, plumbago, nitrate of potash, nitrate 

 of soda, or lime, and carbon. The proportions of these materials the 

 patentee states to be, oxide of manganese forty-two parts, plum- 

 bago eight parts, nitrate of potash, nitrate of soda, or lime, two 

 parts, and carbon fourteen parts ; the carbon to be used, the 

 patentee prefers to be either anthracite coal or wood charcoal. The 

 mode of opei'ation is as follows : the ore is roasted in the usual 

 manner and then melted ; and when in this state, the composition 

 of the four materials named is introduced into the furnace and 

 well mixed with the melted ore. The composition is introduced 

 in the proportion of twenty-five pounds weight to one ton of ore 

 operated upon, .and acts as a flux. The slag rises more rapidly 

 than ordinary to the surface of the melted mass, and is then to be 

 skimmed off. When the workman perceives the metal is in a suffi- 

 ciently forward state of manufacture, a second quantity of the 

 composition in equal proportions is added, and the mass is again 

 stirred and skimmed. Additions of the composition are repeated 

 if necessary, until the copper is in a sufficient state to be removed 

 and operated upon in the usual manner. Should it be considered 

 desirable, the composition may be introduced at any of the subse- 

 quent meltings of the ores, either in addition to, or without being 

 introduced at, the first melting. The patentee does not confine 

 himself to the precise proportions specified of the materials, ncr 

 to the precise mode of operation described, but claims the employ- 

 ment of the compound of oxide of manganese, plumbago, nitrate of 

 potash, nitrate of soda, or lime, and carbon. 



DRESSING ORES OR MINERALS. 



William Bruntom, jun., of Poole, Cornwall, civil engineer, for 

 " certain apparatus for dressing ores or minerals." — Granted Novem- 

 ber 16, 1847; Enrolled May 16, 1848. 



This invention consists in the application of centrifugal force 

 combined with the upward impulse of water in the dressing of 

 small ores. The first part of the apparatus consists of a tank from 

 five to six feet square ; within this is fitted a sieve, having a wove 

 wire or perforated metal bottom, the apertures being adapted in 

 size to the ore about to be dressed. This sieve is fixed upon an 

 upright shaft or spindle, revolving in a bearing at the bottom, and 

 having a turned journal at its upper end. The depth of the annular 

 margin or sides of the sieve is about eight inches. Immediately 

 under the bottom of the sieve a partition, enclosing about one-third 

 of its area, crosses the tank, and having communication with the 

 discharge pipe of a force-pump. On the opposite side of the tank 

 is a receptacle for the ore, and this is supplied by an instrument 

 termed a " skimmer ;" its lower end forming a mouth, and equal 

 in breadth to the semi-diameter of the sieve ; the stem being 

 hollow, and bent at a certain portion of its length (turning down- 

 wards), so that anything passing through it will be deposited in 

 the receptacle attached to the tank. A rotating motion being 

 given to the sieve by means of wheels and pulleys fixed upon thfi 

 upper end of the upright spindle, and the sieve being charged with 

 ore or mineral by means of a hopper placed above it, the mouth of 

 the skimmer is so regulated that, as the whole revolves, the water 

 is forced upwards through the sieve by the action of the force- 

 pump. The ore, by excess of weight, falls through the bottom of 

 the sieve into the tank, and the waste is carried into the mouth of 

 the skimmer, in consequence of the rotating force, and passes 

 thence through the pipe or stem into the adjoining receptacle. 

 The stream of water which is carried with the waste returns into 

 the tank, and is sufficiently clean to be used again. The area of 

 the piston of the pump should not be less than one-third the area 

 of the sieve, and from 00 to 100 impulsions should be given by the 

 pump before the skimmer is set to work ; by this means the parti- 

 cles are raised, separated, and adjusted according to their specifii; 

 gravity and bulk. Should the " orey" stuff be larger than the 

 apertures of the sieve, the feed from the hopper is shut off by a 

 little door that closes its mouth, and a shoot being placed on or 



