1080 SEC. 20. MISCELLANEOUS. 



(10.) 1. MODEL of a PUMP by suction and pressure. 



2. Barometer, by Poleni (1740-1760).* 



3. Barometer, by Amontons. 



4. Barometer, by Cassini. 



5. Barometer (quadrant). 



6. Barometer of Fortin. 



7. Barometer of Fortin, constructed by Bellaui. 



8. Syphon barometer, constructed by Bellani. 



(11.) 1. AIR-PUMP by suction and pressure, by Deieuil. Gives 

 rarefaction to 2 mill., and compression to 10 atmospheres. The 

 effect is double, and the piston does not touch the walls. 



2. Differential manometer of Regnault. 



3. Metallic manometer. 



(12.) 1. DOUBLE SIREN of Helmholtz (Koenig, Paris). 



2. Apparatus by Koenig for the combination of vibrating forces. 

 May also be used for the experiments of Lissajous. 



3. Apparatus by Koenig for the interference of sounds. 



4. Organ pipes with manometrical capsules, by Koenig. 

 o. Apparatus for musical flames. 



6. Analyser of sounds (Koenig). 



7. Acoustic interrupter. 



(13.) 1. HELIOSTAT, made at Padua in 1828 by the younger 

 Tessarolo, resembling, with modifications, that by Prandi. The 

 reflected ray may be thrown in any direction. (Sec Opere Scient. 

 di Bologna, 1824, p. 244, and Santini, Struinenti Ottici, vol. 1, 

 Padova, 1828.) 



2. Heliostat of Silbermann ; made at Paris. 



3. Lantern for electric light, with Foucault's regulator, con- 

 structed by Duboscq.f 



4. Lamp for oxyhydrogen magnetic light, by Carlevaris. 



5. Lamp for the Drummond light. 



6. Regulator for electric light, by Archereau, with reflectors, 

 invented by Prof. Eossetti so as to throw the light in all directions. 



(14.) 1. COMPLETE OPTICAL BANK. 



2. Microscope, by Hartnack. 



3. Microscope, by Amici. 



4. Microscope, by Plossl. 



o. Dialytic telescope, by Plossl. 



6. " Lentiprisma." 



7. Prism for projections. 



8. Spectroscope, for direct vision. 



9. Bunsen's Spectroscope. 



* A constant level in the vessel is obtained by the immersion of a screw, 

 t To this is attached a projection microscope. 



