480 



♦ KNOWLEDGE ♦ 



[Junk 5, 1885. 



takiBg a plane midway between d h and D B bas for radius 



(^-Ds' 



and for circumference — (2d—s). Hence the 

 ' « d 



area of the frustum d A h is equal to the rectangle vmder a 

 line equal to the circumference of K L M and the side 

 d D. This can easily be obtained by an independent 

 geometrical method, the recognition of which I leave to 

 your ingenuity. 



A. Let us next take the volume of tho cone. 



M. We may preferably leave that till next lime. 



(To he continued,') 



WATCH-MAKING AT THE IXVENTIONS 

 EXHIBITION. 



THE display made by the American Watch Company, of 

 Waltham, ilassachu.?etts, is to English eyes not only 

 very attractive but eminently novel. It may be justly 

 regarded as typical of the general bent of human ingenuity 



ductions are not to be despised or derided simply because 

 it is impossible to trace by any show of irregularity the 

 evidence of man's direct handiwork. Big, however, as is 

 the show made by the company at the Inventions Exhibi- 

 tion, it is inadequate to demonstrate the vastness of the 

 factory and completeness with which every little detail is 

 attended to. A few remarks on these points may not want 

 in interest to our readers. In the accompanying illustra- 

 tions, the factory and several branches of the work are 

 depicted. The present buildings were erected in 1878, 

 other and smaller works having been in existence since 

 1850. Fig. 1 gives a fair idea of the general plan upon 

 which the edifice has been erected. It is built on an ex- 

 pansion of the Charles river at Waltham, and is constructed 

 of bricks. It consists of an extensive range of work- 

 rooms, ic, with several long wings and inner courts, de- 

 signed evidently to secure as much natural light as possible. 

 The building is flanked on the one hand by the offices, and 

 on the other by a well-equipped conservatory, the total 

 frontage being 6-4G ft., and the floorage nearly five 

 acres. There are upwards of three miles of work- 

 benches. Nearly everything being done by steam power. 



in the States. There the efibrt clearly is to minimise to 

 the very lowest limit the necessity for hand labour. The 

 causes of this are manifold, not the least being the require- 

 ments of a young but energetic country, teeming with 

 resources only very partially developed. We in England 

 have, somehow or other, become so thoroughly imbued 

 with the idea that a hand-made article is so much better, 

 so much more accurate and reliable than one produced liy 

 machinery, that it is for us a matter of ditKculty to con- 

 ceive the production of so delicate an appliance as a watch 

 almost solely by mechanical means. Nevertheless, it must 

 be apparent, after due reflection, that any imperfections in 

 machine-made appliances are due rather to inaccuracy 

 and imperfection in some slight detail or design, than 

 to a fault in the principle. It is manifest that a tool 

 which is made to perform certain work with definite 

 regularity must, in virtue of that very autonomy, produce 

 better work on the whole than could be furnished with the 

 unaided hand, susceptible as it is to every extraneous in- 

 fluence that may be calculated to interfere with its 

 efficiency as a tool-directing machine. The exhibit under 

 consideration is one which is calculated to materially modify 

 our impressions, and to convince us that mechanical pro- 



a large Corliss engine of 12-5 horsepower is kept going in 

 the engine-house at the rear. The engine drives 10,600 

 feet of main shafting, which, by means of pulleys and beltr 

 ing, drive the machinery — in some cases direct, in others 

 by the intervention of 8,000 feet of wall- rods. Alto- 

 gether, 39,000 feet of belting and 4,700 pulleys are 

 requisitioned. At night-time, or when natural light is 

 insufficient, illumination is aflbrded by 200 incandescent 

 electric lamps and 3,500 gas-jets, involving 22^ miles of 

 piping. As may be gathered from the illustration, but 

 better still from the well-executed model of the factory 

 embodied in the exhibit, extensive grounds surround the 

 building, every efibrt being made to maintain them in as 

 attractive a state as possible. Every attention has been 

 paid to the sanitary arrangements, provision having to be 

 made for 2,500 emploijes, who turn out between them 

 nearly 400,000 watches per annum. 



The works are divided into twenty-five distinct and, in 

 a measure, independent departments. Each communicates 

 telephonically with the central oflice. In these depart- 

 ments, each watch undergoes, it is said, no less than 3,746 

 operations — a fact which few people in this country will be 

 able to realise. 



