ILLUSTRATING ITALIAN SCIENCE. 891 



3. Gnomon, for the rotation of the dioptric. 



4. Dioptric, with pointers and telescope, by Giuseppe Stefani. 



5. Small spherical level from the Tecnomanasio of Milan (1869). 



6. Dioptric, with telescope, by Alemanno, of Turin (1870). 



7'. Small level, with bubble of invariable length, designed by Professor 

 Legnazzi, and constructed by his pupil Francesco Pasini (1875). 



8. Small common level of the Italian tablet. 



9. Praetorian tablet of the Italian system by Rochetti, of Padua, without 



the mirror and the accessory instruments in order to show its con- 

 struction. 



10. Small metrical chain of precision, of 10 meters, which was employed 



in the operations of the measurement of the arc of meridian of 

 France (1802-1817). 



11 . Topographical compass, by Giuseppe Rodella, of the Koyal Observatory 



of Padua (1795). 



12. Praetorian tablet of the German system by Carl Starke, of Vienna, 



without the mirror, in order to show its construction (1856). 



13. Praetorian tablet of German system, by Carl Starke, of Vienna, com- 



plete (1842). 



14. Small level, by Ertel, of Monaco (1874). 



15. Dioptric, with telescope and distance-measurer, by Carl Starke, of 



Vienna (1852) ; an excellent instrument. 



16. Small level of the Starke tablet. 



17. Gnomon and compass of the Starke tablet. 



18. Dioptric and telescope of the Starke tablet. 



19. Metrical chain of 20 metres. 



20. Odometer, by Adams, of London (1791). 



GROUP. IV. LEVELS. 



1 . Aneroid, by J. Goldschmid, of Zurich ; where can be read an eight- 



thousandth part of a millimetre of movement in the sides of the box 

 (1874). 



2. Naudet's olosteric barometer, by Feigestock, of Vienna, which gives 



the one-tenth of a millimetre of atmospherical pressure (1874). 



3. Metallic thermometer of Bourdon. 



4. Naudet's olosteric barometer, by Hirsch, of Florence ; gives half a 



millimetre of pressure (1872). 



5. Naudet's olosteric barometer, by Frescura, of Padua (1873). 



6. Naudet's olosteric barometer, by Feigestock, of Vienna ; like No. 2. 



7. Aneroid barometer, by Bourdon (1859). 



8. Aneroid barometer, by Naudet ; like No. 2. 



9. Metallic barometer, Bourdon, from the Tecnomanasio of Milan. 



10. Olosterical barometer, Naudet, by Feigestock ; like No. 2. 



11. Level with telescope, by Rocchetti, of Padua, with thread micrometer 



(1853). 



12. Level with distance measurer, by Carl Starke, of the Imperial and Royal 



Polytechnic Institute of Vienna (1855) ; an excellent instrument. 



13. Pendulum level with two telescopes ; an historical piece ; must be very 



old ; the telescopes are not achromatic. 



14. Level with telescope, by Rodella, of Padua (1820). 



15. Level with mirror, rather old. 



16. Level with distance measurer, by Starke and Kammerer, of Vienna 



(1876) ; an exquisite instrument. 



17. Pocket level, by Carl Starke, of Vienna (1850). 



18. Level with communicating tubes ; an old model (1810). 



