ON A CiAUOE Foil SMALL .S( UKW; 



2i):\ 



lust not 

 ) thread 

 olvcd in 

 ring Uic 



mbcr oC 

 le others 

 10 Whil- 

 it is 80 

 ly that it 

 >ars from 

 lid rathev 

 lufacturc, 

 •which is 

 ice. The 

 e than is 



all sc'rews 

 L'd bv the 



V hit worth 



(■ the crest 



;h,and the 



somewhat 



bribed, this 

 njrs (ith at 

 loreover, to 

 iisideration 

 may be of 

 ble lor the 

 mditions in 

 the thread, 

 ) at the top 

 le of thread 

 espectively. 

 cpiire to be 

 meters, and 

 icommenda- 



nob to ^th 

 boasandtlis 

 T the seriea 

 I succession 



0" mm. 



Iters. 



liUy dccreas- 

 lat only two 

 lus obtained 



Ivd of small 



screws, international in its character, Knglisli manufacturers of screw.", 

 screw-plates, Ac, adopt (lio exact pitches «?ivcn in millimetres in Colnmn 

 VI., wliich, as explained in par. 1», can, if required, be originated on an 

 I'liiglish lathe. Fnrther, in view of the fact that small .screws and screw- 

 plates, while nominally alike, will not nnfrequently difllr considerably a<? 

 regards their number of threads i)er inch, the practice of designating such 

 screws by their number of thi'eads per inch should not be adopted. For 

 reference, however, tlio approximat(! number of threads per inch, as 

 calculated i'rom the pilch given in Column VI., are given in Column IV. 



(J.) Tliatthe designating numbers given in Column 1., being the indices 

 of the powers to which OP is rai.sed to obtain the pitch, be punched against 

 each hole in the sci-ew-plale, and that, if thouglitdesiiable, its diameter in 

 thonsaiidths of an inch (Column II.) might be punched side by side with 

 this number. 



•J.'). In his SiisIi'iukIi'ihi; (!>.'.■< ois Ilorlogrrcn, Prof. Thury has done for 

 the small screws used by watch, clock, and scientific instrument makers 

 what was done forty years ago by Sir J. Whitworth for the larger screws 

 used by engineers ; and, like the admirable sy.stem introduced by the 

 latter, tlu; scheme here advocated is based on the data obtained by measur- 

 ing the several dimensions of many screws accepted by practical men 

 as being well-proportioned. 



20. The Committee has had an opportunity of examining both screws 

 and screw-plates (^for the smaller .screws) made on this system, which it is 

 convinced will satisfy all the demands of practice. The Committee can, 

 therefore, confidently I'ccommend its adoption by the British As.sociation, 

 subject to the slight moditication discussed in par. t2o ; and it feels that an 

 important incidental advantage would be the sui)p«)rt it would at once 

 receive on the Continent, and the consequent increased rapidity with 

 which it might be expected to come i)ito general use ; for it cannot be 

 doubted that its recognition by so important a body as the Biitish As.so- 

 ciation would have considerable influence in establishing tho system 

 abroad. 



[The ri'commendation for the appointment of this Committee having 

 failed to reach the Committee of Recommendations at .Southport in time 

 to allow of its sanction by tho General Committee, the Council at tlieir 

 meeting on November ('», 18H3, requested the Committee to continue th(!ir 

 labours, and undertook to recommend to the (ieneral Committee at 

 Montreal that this Report be printed among tho Reports.] 



Report of the Convniitiee, consistuuj of Sir FiuvDEIiick IIka.mwf.ll 

 {Sccntav}/), Professor A. W. Willl\mson, Professor Sir William 

 Thomson, :Mr. St. John Vincent Day, Sir F. Ahel, Captain Douo- 

 LA.s (lAL-roN, Mr. E. 11. Caruutt, Mr. Maci{ORY, .Air. IT. Thueman 

 Wood, Mr. W. H. Baklow, Mr. A. T. Atchlson, Mr. K. E. Weh- 

 .sTER, Mr. A. CARl•^L\EL, Sir John Lubugck, Mr. Theodore Aston, 

 iind Mr. James Brinlees, appointed for the purpose of ivatchhuj 

 and report ill g to the Council on Patent Legislation. 



The Act for the reform of the Patent Laws, passed in 1884, having 

 only come into operation in January of the present year, sufficient time 

 has not yet elapsed for its working to be tested. The Committee, there- 



