4 Introduction. 



Next to it come the university towns and the seats of polytechnical colleges, 

 in which, beside the instrument makers holding official appointments in univer- 

 sities and institutions, a number of other instrument-makers are established.. 

 This local association of practical manufacture and scientific research and the 

 daily intercourse of makers and scientists greatly favours, by mutual reaction,, 

 the growth of this branch of applied science. Beside in Berlin, important 

 centers of mechanical art are to be found in Munic, where the great achieve- 

 ments of Fraunhofer and Reichenbach are continued by their successors, and 

 in Hamburg, which, beside excelling in astronomical and surveying instruments- 

 and appliances for spectrum analysis, possesses, as a natural consequence of its 

 importance as a sea-port, prominent works for the manufacture of chronometric 

 and nautical instruments. In several manufacturing towns the construction of 

 electrical measuring instruments and electro-therapeutical appliances forms a 

 prominent feature, e. g. in Berlin, Frankfort-on-the-Main, Stuttgart and Er- 

 langen. Important branches of instrument manufacture are also found in many 

 other towns, where production is favoured by special local conditions. 



It would be impossible to here define the entire extent of the German 

 scientific instrument trade; we must, therefore, limit ourselves to a short 

 sketch of its compass. 



The general stamp of German astronomical instruments corresponds 

 to the intrinsic character of the German methods of astronomical research. 

 The intruments are not so much distinguished -for their size, to which much 

 importance is attached in America, as for their rigidity and greatest possible 

 exactness and highest finish of the constructive details; more importance than 

 to size is attached to ingenious arrangements calculated to minimise the effect 

 of instrumental errors. Important improvements have been made in this 

 direction in the construction of meridian circles of portable transit instruments- 

 and of zenith telescopes. Delicately accurate astronomical levels, whose exces- 

 sively laborious production implies the exercise 6f the greatest patience and care r 

 have at present reached the highest standard of perfection in Germany. -- The 

 reputation of German surveying instruments has gained still further ground 

 during the latter years. Recent ordnance survey and measurements of the earth 

 shape have led to many improvements in theodolites, levelling instruments and 

 tacheometers, and the wants of explorers have suggested particularly compact 

 constructions of these instruments. In the case of the instruments intended for 

 ordinary surveying special attention is paid to arrangements for conveniently 

 centering the instruments and to the stability and handiness of the stands. Also 

 instruments for geophysical research have in recent years undergone important 

 improvements; amongst others, registering mareographs are now made of a 

 degree of perfection which was hitherto unknown. In consequence, almost 

 exclusively German instruments are used in the ordnance surveying work of 

 many countries in all parts of the globe. The manufacture of nautical instru- 

 ments, sextants, octants, mariner's compasses and so forth, has, thanks to the 

 united efforts" of the Imperial Admiralty and the mechanical trade, made such 

 progress that now many instruments which formerly had to be obtained from 

 abroad are not only made in Germany in good quality but even of a superior 

 kind to those made abroad. Particularly noticeable progress originating in the 

 work of the Imperial Assize Commission, has been made in metrological 



