2:s 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



fSfiPTEMBEB, 



oal inconvenience which would arise from permitting such a course 

 to be pursued at the present time. AV'e would suggest that all 

 patents fur new inventions might be granted as of course for the 

 United Kingdom of Great Britain and Ireland, and that the pro- 

 c:eedings for obtaining a patent should take place in this kingdom 

 only. The speciiication in that case should be required to be en- 

 rolled in each of the three capitals. 



'l"he proceedings for a patent, whether in England, in Scotland, 

 or in Ii-eland, must originate by petition to the crown; and it 

 would seem that Scotch and Irish inventors almost invariably take 

 out patents in England, if not previously to, at all events imme- 

 diately after, taking out their Scotch or Irish patent. The advan- 

 tage therefore, that would arise from the course recommended, in 

 the saving of fees »nd other charges, and of time and trouble, 

 would be at least as great to the Scotch and Irish patentee as to 

 the English. Cases, however, may occur in which it might be ad- 

 visable to have the opinion of the crown lawyers in Ireland or in 

 Scotland previously to her Majesty being advised to grant her let- 

 ters patent. 



We would therefore suggest, that if it should be determined to 

 give the power of granting patents under the single Great Seal of 

 the United Kingdom, which should have effect in the three king- 

 doms equally, a discretionary power should be given to the secre- 

 tary of state, enabling him, should he see fit so to do, to refer the 

 petition to either the attorney or solicitor-general for England, 

 the attorney-general for Ireland, or the lord advocate of Scotland. 



If the views which we have formed with regard to the abolition 

 of patents in some cases, and the simplification in all of tlie pro- 

 cess of passing them, shall be approved of, the retention of the 

 Signet Office as a distinct brancli of the department of tlie secre- 

 tary of state will become unnecessary. 



Abolition of Signet Office recommended. — We therefore recommend 

 that the Signet ()ffice be abolished, and whatever business may re- 

 main to be transacted connected with the Signet be transferred to 

 the Home-office, together with such of the records, &c., now depo- 

 sited in the Signet Office as may be necessary for the purposes of 

 official reference. The remainder might be consigned to the cus- 

 tody of the Master of the Rolls, or to tlie State Paper Office. 

 The amount of business thus transferred to tlie Home-office could 

 not be very considerable. 



Recommendation respecting Privy Seal Office. — It would still be 

 necessary to retain an establishment for the office of the Lord 

 Privy Seal, though the duties of that office would be much re- 

 duced, and would not occupy the time of more than one clerk The 

 business of the Signet and Privy Seal Offices is at present con- 

 ducted in the same house in Abingdon-street, for which a rent is 

 paid by the public. The abolition of the Signet Office would 

 render the retention of this house unnecessary. If apartments 

 could be provided for the future accommodation of the Loi'd Privy 

 Seal's department in some one of the public buildings in White- 

 hall, it would be a great convenience in the transaction of the busi- 

 ness of tliat office. 



We think it desirable to refer to the Act of 1 Vic, c. 73, by 

 which the Queen is enabled to confer certain powers and immuni- 

 ties on trading or otlier companies by means of letters patent. 

 The operation of that act will not be in any way aiFected by the 

 changes proposed in this Report, which have reference only to the 

 mode of passing lettei's patent. 



In concluding our Report, we beg leave to express a hope that 

 the interests of individuals who may be affected by our recommen- 

 dations and suggestions may be duly considered, and that compen- 

 sation may be awarded to those whose tenure of office gives them 

 » title to claim it. 



MiNTO. 



G. CoBNEWALL LeWIS. 



H. Rich. 



On the Manufacture of Enamelled Copper at Canton. — When the copper 

 has been shaped into the desired form, it ia to be cleansed, but not scoureJ, 

 and afterwards wetted with water, and sprinkled with the enamelling com- 

 position intended to form the ground, which may be either white or co- 

 loured. The article is then put in a muffle heated by means of dry Nankeen 

 coal (this is found to be the best fuel). When the ground has been produced, 

 the article is withdrawn from the muffle, and covered with an iron bell, in 

 Older that it may cool shortly j the ground may be then ornamnnted in the 

 same manner as porcelain, and again passed lhri)nj;h the ninffle. Seveial 

 specimens of enamel, and colours npon enamel, have 'teen deposited at the 

 Royal manufactory at Sevres, in order that the manufacturers in France may 

 he made acquainted with the art. 



IMPROVED LOCOMOTIVE BOILER. 



On an Improved Locomotive Boiler. By Mr. Raihsbottom, of 

 Manchester. — (Paper read at the Institution of Mechanical En- 

 gineers, Birmingham, July 25th, Charles Beyer, Esq., V.P., in the 

 Chair. 



Without discussing the merits of the various arrangements and 

 dispositions of the working jiarts of locomotive engines, the author 

 of the present paper proposes to make a few observations respect- 

 ing the most vital part of these machines, that upon which 'the 

 satisfactory performance of all the details must necessarily depend 

 — namely, the Boiler. 



Before proceeding to the immediate subject of this paper, it is 

 proposed to point out one or two objections to locomotive boilers 

 as at present constructed, which experience has brought under the 

 author's notice; and then to describe a form of boiler which ap- 

 pears to him in some degree calculated to remedy the defects which 

 will be referred to. 



It is scarcely necessary to observe that the absolute power of a 

 locomotive, or any other steam-engine, is strictly projiortioneJ to 

 the quantity of steam which the boiler of such engine can produce 

 in a given time; and chemists are generally agreed that tlie quan- 

 tity of atmosplieric air required (or oxygen which is the supporter 

 of combustion), as well as the quantity of fuel, is in direct propor- 

 tion to the quantity of water evaporated; or in other words, to 

 produce mi>re steam, it is not only necessary to supply more fuel, 

 but also more atmospheric air in proportion to the quantity of 

 steam produced. 



It is well known that some of the locomotive engines built at 

 the present day have from two to three times as much heating sur- 

 face as those built about eight or ten years ago, and consequently 

 when performing a proportionately increased amount of duty, they 

 require from two to three times the quantity of air forcing through 

 the fire in the same time. 



The working parts of these engines have also been increased in 

 dimensions; the cylinders from 12 inches to 15 and 16 inches 

 diameter, the stroke from 16 inches to 20 and 24 inches, and the 

 driving-wheels from i ft. 6 in. to 6 feet diameter, and in many cases 

 even more. 



Notwithstanding all these enlargements and imjirovements, 

 there are however two elements which have been but slightly 

 changed— namely, the diameter of the blast-pipe, and the diameter 

 of the cylindrical part of the boiler; and as the whole of the steam 

 (after having performed its office in the cylinders) is driven in a 

 forcible jet up the chimney for tiie purpose of producing the ne- 

 cessary draught through the fire, and as the power required to 

 produce this jet is so much taken from the gross power of the en- 

 gine, it follows that the smaller the blast-pipe is in proportion to 

 the total heating surface of the boiler, the greater will be the re- 

 sistance to the action of the piston, and the greater the loss of 

 power on this account. 



From observations made upon engines under the author's imme- 

 diate superintendence, it appears that whilst the heating surface of 

 locomotive boilers has been increased from 400 square feet (in the 

 year 1842) to 987 square feet (in the year 1846), the blast-pipe has 

 not been in the slightest degree enlarged, but on the contrary in 

 the latter case has been reduced in area in the proportion of 12.j 

 to ^\ square inches. So that upon dividing the total heating sur- 

 face or area (f production, as it may be termed, by the size of tlie 

 blast-pipe, or area of eduction (assumed as unity), the following 

 very instructive results are obtained : — 



-. , r, I ,.rL u -1. Area of Heatin? 



No. of EnglDe. When built. b,^^j p^p^ g^„.^J 



24 1842 1 4';0» 



2(1 1M42 1 6044 



25 1S45 1 7'Jill 



m is4ii 1 l2aiio 



In the last case, then, it appears that the heating surface has 

 been increased nearly three-fold in proportion to the size of the 

 blast-pipe, as compared with Engine No. 24; and the reason will 

 be obvious wlien it is stated that the Engine No. 30 is only of the 

 same diameter as the first-named (No. 24), and consequently tliat 

 the flue-room (which as a general rule will be as the square of the 

 diameter of the lioiler), has been but slightly increased, the extra 

 heating surface having been mainly obtained by enlarging the fire- 

 box, by putting in a mid-feather, and by increasing the length 

 rather than the number of tubes. 



It is not necessary to inquire how far the diameter of the cylin- 

 ders may affect tlie size of tlie blast-pipe, nor to ascertain the 

 amount of ])Ower whidi the blast-pipe absorbs, though it may be 

 stated that experience proves it to range from 10 to 20 per cent, of 

 the gross power of the engine, according to the number, diameter, 



