II. MINING. 735 



plate, which ride over the face of the semi-circle when the plate is inclined 

 for the purpose of taking a sight in steep mines. When the arc is not re- 

 quired, it is simply folded down on the outside of the compass-box. In 

 practice this is found to be an exceedingly convenient arrangement. 



339Ob. One 12-inch Circular Protractor, divided to 15 

 minutes for plotting in connexion with the dial. 



Joseph Casartelli. 



3391. Mine Compass, with arrangement for suspending 

 needle 7 cm. long, circle graduated in degrees. 



A. and R. Hahn, Cassel. 



3392. W. Konig's Telescope Mine Compass, with level 

 and graduated arc, together with Horold's centre foot-plate in box 

 with lock. 



Royal Prussian Upper Mining Court for the Provinces of 

 Silesia, Posen, and Prussia (Breslau). 



This instrument is used by mine surveyors, and at official revisions of 

 mine surveys. 



3393. Complete Mine Surveying Implements, consisting 

 of compass, suspender, graduated arc, additional plate, pocket arid 

 case for the additional plate. Otto Fennel, Cassel. 



3394. Steel Measuring Band for mining surveyors, in 

 case. C. Osterland, Freiberg. 



Is devised to be used principally in conjunction with a mine theodolite 

 constructed by the exhibitor, and is supposed to render skilled assistance in 

 measuring of less importance to surveyors. 



3395. Head with screw for the steel band. 



C. Osterland, Freiberg. 



3396. Travelling Box Compass, with brass support adapted 

 for levelling with a small suspending apparatus, graduated arc, and 

 appurtenances. C. Osterland, Freiberg. 



Constructed for travellers in thinly populated countries, and is adapted for 

 attaching to the saddle. 



3397. Mine Surveying Instrument, consisting of compass, 

 suspending apparatus, and additional plate, graduated arc, and two 

 cases. A. Lingke and Co., Freiberg, Saxony. 



3397a. Henderson's Hypo-thonite, with its stand, are 

 improved forms of the same kind of instrument generally in use for 

 rough surveying, especially in underground workings of collieries 

 and other mines. Ridley Henderson, Timsbury. 



