784 



SCIENCE. 



[N. S. Vol. XII. No. 308. 



made in Germany and exported abroad in 

 very large nnmbei's. Tlie growing applica- 

 tion of the electric current as a curative 

 agent in operations and for the illumina- 

 tion of internal cavities of the human body 

 has caused this department of industry to 

 develop considerably both technically and 

 commercially. To this group of appliances 

 belong the various kinds of Rdntgen ray 

 apparatus, which are made and exported in 

 stupendous numbers. Great importance 

 attaches also to the manufacture of physio- 

 logical and biological instruments, which 

 engages the attention of several prominent 

 firms. 



VIII. The manufacture of educational 

 appliances has grown in proportion to the 

 development of the methods of practical 

 demonstration in elementary as well as in- 

 termediate schools and technical colleges. 

 Tlie German output of educational appli- 

 ances has at present reached a truly as- 

 tounding magnitude. This is mainly due 

 to their cheapness, simplicity and their 

 suitable size. The laboratory appliances 

 required for scientific investigations com- 

 prise naturally the finest and costliest in- 

 struments made. 



IX. The manufacture of drawing and 

 calculating instruments employs a large 

 number of German mechanicians. Excellent 

 drawing instruments and other appliances 

 for drawing, cartography, etc., are exported 

 to all parts of the world. German mecha- 

 nicians have likewise succeeded in consider- 

 ably improving Thomas's old calculating 

 machine. 



X. In addition to purely scientific in- 

 struments, a very large number of appli- 

 ances are in constant requisition for special 

 iudastrial purposes, and many a mecha- 

 nician finds constant employment in this 

 department. Besides, much thought and 

 skill is brought to bear upon the needs of 

 mechanical workshops. Formerly every 

 mechanician made his own tools, and in 



many instances this is still done. Many 

 changes have, however, been wrought in 

 this respect by the influence of the Amer- 

 ican system of manufacture, in which, it 

 should be added, Germans have a consider- 

 able share. Prominent mechanicians and 

 engineers began to devote themselves more 

 or less exclusively to the manufacture of 

 special tools for philosophical instrument- 

 making, and now form an important inde- 

 pendent branch of industry. 



In conclusion, we have to draw attention 

 to the separate exhibition of the Imperial 

 Physical and Technical Institute, which 

 could not be mortised into the general plan 

 of the Joint Exhibition. The aims of this 

 Institute, the greatest of its kind in the 

 world, have already been explained. The 

 exhibits of the Institute serve to illustrate 

 in a concise form several spheres of its ac- 

 tivity. 



The commercial importance of the me- 

 chanical and optical trade of Germany is 

 commensurate with its reputation, as will 

 readily be seen from the following table 

 showing the export of scientific instruments 

 during 1898 : 



Net weight Value In 

 kilos. Marks. 



Astronomical, optical mathe- 

 matical, pbysical and elec- 

 trical instruments 218,900 8,975,000 



Raw optical glass (flint and 



crown) 124,900 625,000 



Optical glasses (spectacles, 

 reading-glasses, stereoscope 

 glasses) 224,200 3,139,000 



Terrestrial telescopes, field- 

 glasses, opera-glasses, m'ntd 

 spectacles, etc 33,900 1,526,000 



Total 601,900 14,265,000 



The export has been trebled within ten 

 years ! 



Another measure of the magnitude of the 

 mechanical and optical trade of Germany 

 may be obtained from the number of manu- 

 facturing establishments and their em- . 

 ployes. 



