870 SEC. 19. EDUCATIONAL APPLIANCES. 



acquisition of these collections, as indeed for the founding of the appropriate 

 schools, comes from a special fund, which owes its origin and continued 

 maintenance to some clauses in the older German mining laws, according to 

 which the revenues of certain mines are applied to school and church purposes. 

 Through the rapid growth and development of the Silesian mining industry, 

 this fund has risen to the value of 25,000/. per annum. 



The above-mentioned schools are not to be mistaken for the mining schools 

 proper, or the schools serving as preparatory institutions to these latter, both 

 of which are intended for grown-up pupils. 



4219a. Apparatus employed in teaching, for exhibiting the 

 action of Electric Currents on Currents of Magnetism. 



W. Gloukhoff y Warden of Russian Standard Measures. 



In this apparatus the mode of suspension of the movable conductors is 

 entirely new, and consists of a brass tube A, B, C, D, through which passes 

 an insulated brass wire E, F; the wire and the tube have on their tops the 

 metallic cups E and D, filled with mercury. Into the cup E the steel point of 

 suspension and one end of the movable conductor are plunged, and into the 

 cup D the other end. 



4220. Universal Rotation Apparatus with Twenty-six 

 Auxiliary Apparatus, viz.: 



1. Centrifugal pendulum. 



2. Spheres of different weight. 



3. Globe, 100 grammes in weight, movable horizontally, with 

 spring balance, on which the centrifugal force can be directly 

 measured. 



4. Two oblique glass-tubes for different kinds of liquids. 



5. Glass-balloon. 



6. Apparatus for demonstrating the flat spherical form of the 

 earth. 



7. Apparatus for flattening of an oil-globule (King of Saturn). 



8. King, chain, ball, cylinder, suspended on a cord. 



9. Ball, suspended on a long string, for Foucault's pendulum 

 experiment. 



10. Glass-balloon for demonstrating the rising of fluids. 



11. Model of a centrifugal blast. 



12. Model of a draining and drying apparatus. 



13. Apparatus by Coulomb, for causing water to boil by friction. 



14. Syren-disc, playing one accord. 



15. Savart's toothed wheels. 



16. Disc with mirror surfaces and flame-manometer for acoustic 

 flame-images. 



17. Stroboscopic cylinder for demonstrating various oscillations 

 according to Quincke. 



18. Colour-discs. 



19. Oscillating prism. 



20. Glass-balloon for producing Newton's colour-rings in thin 

 metal plates of fluid. 



21. Stroboscopical discs on the systems of Dove,Poggendorff, &c., 

 illuminated by Geissler's tubes. 



