SCIENTIFIC APPARATUS APPLIED IN 

 MINING. 



THE multitudinous appliances which are used in the operations 

 of mining may all be termed, in a certain sense, scientific appa- 

 ratus, from the rough hammer wielded by manual labour to the 

 mighty steam-engine doing in a small compass the work of five 

 hundred horses. But although the proper construction and appli- 

 cation of these numerous instruments depend wholly on scientific 

 principles, they appear to pass out of the category of scientific 

 apparatus, when they are once merged, as implements, in the every- 

 day work of the establishment. 



An exception may be made in the case of those instruments 

 which are employed for measuring and registration of directions, 

 of meteorological phenomena, and of numerical problems ; but 

 the line of demarcation must nevertheless be a somewhat arbitrary 

 one, which is to separate the objects suitable to the present Exhi- 

 bition from those examples of the expression of scientific prin- 

 ciples in machinery, which would be more in place in an industrial 

 exhibition. 



DIALLING APPARATUS. 



In determining the linear direction of the veins and other reposi- 

 tories of the useful minerals, and in laying down on paper the 

 position and extent of the workings of mines, the magnetic needle 

 has long been employed. About A.D. 1550, George Agricola 

 (Bauer) describes at full length the construction of the instrument 



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