m 



THE FARMER'S MAGAZINE. 



parative perfection attained under each head, to be arranged 

 as follows — 



Portable Steam Engines. 

 In addition to tlie tabular form used in these trials, hitherto 

 stating the actual power, coasamption of fuel, price, &c., of 

 th2 competing engines, a separate form should be provided, 

 with the qualifications for adjudication arranged, and the 

 amount of credit due to each represented by points, thus— 

 Durability combined with excellence of materials 



and workmanship •• 10 



General excellence of design, as affecting the sim- 

 plicity of the engine, and rendering the working 



parts easy of access 10 



Economy in the consumption of fuel 8 



Portability 6 



Price per horse-power 3 



Exhibitors should not be restricted as to the construction or 

 dimensions of the engines or boilers. 



Each engine with the dynamometer should stand under a 

 covered building during trial. 



The coals to be consumed by the competing engines should 

 be Carefully picked over, and broken to pieces of a uniform 

 size ; all dirt and rubbish should be thrown out, and each 

 competitor be served from a quantity of coal of uniform 

 qua'ity, 



III conducting the trials of fixed engines, the same system 

 may be adopted ; each competitor should send to the show 

 such a boiler as he would supply with the competing engine, 

 and after tlie trial of the engines on the dynamometer, if no 

 means are provided for ascertaining by experiment the evapo- 

 rating power of these boilers, the judges should carefully 

 examine therii and give credit for their various points of excel- 

 lei:ce, as iu the tabular form suggested for the portable 

 engines, substituting for "portability," comparative cost of 

 er<.'cting the necessary building, constructing the flues, and 

 fixing the boiler, and the probable cost of removing it if re- 

 quired — this is a very important point in a farmer's engine. 

 Thrashing Machines. 



The same tabular form should be co:itinned as was adopted 

 at the society's trial at Carlisle. 



The corn to be thrashed should be carefully velecled of a 

 u iform quality. 



The trial of each machine should continue for at least half 

 an hour. 



That the produce delivered by each machine during the 

 trial should be carefully weighed, as no correct estimate of the 

 amount of work performed can be obtained by any other meang. 



Dressing Machines. 

 A better method of ascertaining the merits of these ma- 

 chines than that adopted by the judges at Carlisle, cannot be 

 sugi;ested. The follo\ving tabular form may be adopted with 

 rtference to the points for adjudication — 



Duty done iu reference to power 15 



Quality of work done 15 



Durability and fai'ility for repair .. .; .. .. 14 



Simplicity of construction 10 



Excellence of material and workmanship 10 



I'lice 5 



Chaff Cutters. 



Every competing machine should cut the same length of 

 chaff, and exhibitors shoi.ld be informed the length decided on 

 by the society, as long before the trial as possible, and no 

 work should be recognised by the judges which exceeds the 

 stipulated length. 



The same tabular form, as recommended for the dressing 

 michine, may be used to advantage for the chaff cutters. 



Leiston IForks, Garrett & Sons. 



Saxniundliam, iVou. 2, 1857. 



James Hudson, Esa., 12, Hanover-square, London. 



Sir, — In compliance with the invitation of the Koyal Agri- 

 cultural Society to express an opinion as to the future prizes 

 for steam engines, and fearing I may be prevented attend- 

 ing to-morrow, I beg to hand you the following observations, 

 to lay before the Council : 



Looking at the late trials of steam engines, it will be ob- 



served how seldom, if ever, have the prizes for fixed and port- 

 able engines been awarded to the same makers. The trials 

 for fixed engines being made with the society's boiler, puts 

 every maker on the same level, and shows which is the best 

 engine, and the comparative merits of each ; hence we may 

 assume that if the maker of the prize fixed engine fails in 

 taking the prize for the portable engines, the deficiency must 

 be in the boiler and connections. Messrs. Kansoraes have for 

 some years past taken the prize for fixed engines, while that 

 for the portable engines has, I believe, invariably been given 

 to the engine with the boiler of the largest capacity. Take 

 for instance the Carlisle trials, the prize engine had a boiler of 

 nearly double the capacity of that used for trying the fixed 

 engines, and was only called an ej(//ii<-horse power. 



Tlie tube surface of 8-hor3e commercial engines varies from 

 120 to upwards of 200 feet area of tube surface only, while 

 the following table, taken from the entries oi the society's 

 meetings, shows a variation of from 5 to 10 square inches of 

 piston per horse power : 



Cylinder. Ins. stroke. Revolutions. 



Six-horse engine .. 6^ .... 10 .... 120 



8f .... 13i .... 130 



„ .. n .... 12 =... 120 



Seven-horse engine, . 7 •■.. H .... 150 

 „ .. 8i .... 12 ,,.. 130 

 „ ., Si ,.., 14 ,.., 120 



Eight-horse engine.. 8^ 14 120 



„ ,, 9 .... 12 .... 120 

 „ .. 10 .... 24 ,,.. 60 



„ .. 7J .... 12 .,., 130 

 Shewing a great discrepancy iu the area of the cylinder, pro- 

 portionate stroke, and velocity of the working parts ; in fact, 

 as much difference iu the engines as iu the boilers them- 

 selves. 



I think it is necessary to establish a double trial, first as to 

 (he capacity of the boiler, next as to the duty of the engine. 

 I would suggest that a hand-pump fitted with one of Siemens's 

 (or other acknowledged) water meters be attached to each 

 portable engine, either at the suction-clack or elsewhere, the 

 us\ial quantity of coal, 14 lbs. per horse power, being allotted 

 to each engine, and the water-level maintained ; the evapora- 

 tive power of the boiler will be found in the number of pounds 

 of wattr evaporated by each pound of fuel, no artificial 

 draught being employed, the result must be indisputable. 



On the second trial being conducted as hitherto, the duty 

 of the engine and boiler will be found, and by comparing the 

 two results, the power absorbed by the machine itself by back 

 pressure friction, &c., will be ascertained. 



These experiments will forma guarautee for good workman- 

 ship, and the report of the judges giving the result of the 

 double trial, wilt not award the prize to the excessive boiler 

 surface, but to the general efliciency and proportion of both 

 enjiine and boiler. 



It will be necessary for the council to establish some fixed 

 data for the proportions, whether 10 inches of piston and 20 

 feet of heating surface, with the Admiralty rule of 247 feet 

 for piston per minute, and three- fourths of a square foot of 

 firegrate surface per horse power, or such other proportions 

 as may by them and their en(.'ineer be deemed most suitable; 

 these are, however, about the proportions of engines built on 

 the Clyde for SOlbs. pressure. 



Simplicity of arrangement, with due regard to strength and 

 lightness, must not be lost sight of, and the price and weight 

 should form an item of consideration, particularly in portable 

 engines. 



Should these remarks be found worthy of the consideration 

 of the council, and lead to the adoption of a rule for com- 

 mercial engines, it will prove a boon to the farmer, and I shall 

 have the satisfaction of knowing that my ideas are borne out 

 by others. 



I am. Sir, yours very respectfully, 



John Gray, of John Gray & Co. 



Uddingston-by-Glasgow, Nov. 2nd, 1857. 



[Copy, as forwarded by Messrs. Holmes and Sons to the 

 Mark Lane Express."] 



Prospect Place Works, 



Norwich, Norfolk. 

 Gentlemen, — We beg to hand you our opinions and sug- 

 gestions relating to trials of steam engines, &c., as follows : 



