ON A GAUGE FOR SMALL SCREWS. 3ll 



(Dr. Siemens) is one of the Society of Arts Committee wliicli prepared 

 the Bill. 



The Committee request that they may be reappointed, and that the 

 grant made to them in 1880 of 5?. may be renewed. 



Report of the Committee, consisting of Sir Joseph Whitworth, 

 Dr. C. W. Siemens, Sir Frederick Bramwell, Mr. A. Stroh, 

 Mr. Beck, Mr. W. H. Preece, Mr. E. Crompton, Mr. E. Kigg, 

 Mr.' A. Le Neve Foster, Mr. Latimer Clark, Mr. Buckney, and 

 Mr. H. Trueman Wood (Secretary), appointed for the purpose 

 of determining a Gauge for the manufacture of the various 

 small screius used in Telegraphic and Electrical Apparatus, in 

 Glockiuork, and for other analogous purposes. 



1. This Committee was formed by the General Committee of the British 

 Association assembled at York in August and September, 1881, for the 

 purpose of determining a gauge for the manufacture of the various small 

 screws used in telegraphic and electrical apparatus, in clockwork, and 

 for other analogous purposes. 



2. At that meeting a paper was read by Mr. Preece pointing out the 

 desirability of establishing such a gauge. Although the Whitworth 

 gauge is almost invariably adopted for the bolts and screws used in mill- 

 work and engineering in England, no general system has been hitherto 

 applied to the smaller screws used either in clockwork, philosophical in- 

 strument work, or in the numerous practical applications of electricity 

 that are now rapidly becoming so important. In fact, at the present time 

 gauges and screw plates almost equal in number the makers engaged in 

 the trade. One instance was brought to the attention of the Committee 

 by a manufacturer who had to execute an order for railway signal appa- 

 ratus in accordance with three sample instruments containing among 

 them twenty-one screws of different threads, not one of which happened to 

 be in use in his shop. There is now no recognised form of thread, no 

 specified number of threads per inch — in fact, no generally accepted gauge 

 based on practice and experience. Great inconvenience is felt in providing 

 for repairs, which are in consequence more costly and less efficient. 



The employment of some coherent and uniform system is manifestly 

 required. It not only would render repairs easier, speedier, and cheaper, 

 but it would introduce interchangeability of parts, and further the exten- 

 sion of piecework ; and it would reduce the equipment of workshops with 

 special and costly tools. 



3. The subject of uniformity in screws has been very warmly taken 

 up by the Societe des Arts de Geneve, which appointed a Committee 

 in December 187G, who after assiduous labours issued a repoi't in 1878. 

 The system proposed by them has been very fully described by Professor 

 Thury in two pamphlets published in Geneva.' The Committee collected 

 numerous screws of all sizes from matiy factories, measured them care- 



' System atique des vis Jlorlotjlres, Geneva, 1878. Xotice sur le Systimc des vis de 

 la Filiere Suisse, Geneva, 1880. 



