III. SURVEYING. 765 



23. Improved construction, with differential wheels. 



24. Improved construction, after G. Starke. E., p. 73 (1870). 



25. Improved construction, after Amsler-Saffon (1870). 



26. Construction according to Amsler-Saffon with electro-magnetical 

 numbering apparatus (1873). E., p. 73. 



Illustrations of the Improvements in the Construction of Planimeter s. 



27. Polar planimeter, after Amsler (1856). 



28. Momentum planimeter (Integrator), after Amsler (1856). A., 4 part, 

 p. 36, E., page 81. 



29. Polar planimeter, after Miller and Starke (1856). A., 4 part, page 24. 



30. Polar planimeter, after Coradi and Ott (1874). 



31. Planimeter Wetli, Starke (1850, 1871). A., 4 part, page 8, E., 

 page 82. 



Illustrations of the Improvements in the Construct ion of Levelling Instruments* 



32. Vitruv's water-level (63 before Christ, 14 after Christ). 



33. Water-level, after Picard (1620-1682). 



34. Water-level, after Huyghens (1629-1695). 



35. Water-level, after de la Hire (1704). 



36. Water-level, after Homer (1644-1710). 



37. Channel level (Picard). 



38. Mercury level, after Keith (1790). 



39. Vega's levelling diopter (1754-1802). 



40. Liesganig's water level (1719-1799). 



41. Sisson's water-level (18th century). 



42. Stampfer's levelling diopter (1839).. F., page 24. 



43 1 . Hogrewe's levelling instrument (1800). 



43 2 . Pocket levelling instrument, after G. Starke. F., page 33. 



43 3 . English levelling instrument, by Cooke and Son. E., page 65. 



44. English universal levelling instrument, by Cooke & Son. 



44 2 . Levelling instrument, with Stampfer's levelling screw (1836) A., 

 page 197. 



45. Universal levelling instrument, with Stampfer's levelling screw, after 

 G. Starke (1867), F., page 146, and G. 



46. Universal levelling instrument with telescope, after G. Starke (1867). 

 F., page 174, and H. 



47. Tachymeter, after G. Starke (1872). F., page 103, and I. 



48. Polymeter, after Jahns (1873). K. 



49. Tachygraphometer, after Wagner (1869-1871), constructed by Fennel. 

 L. 



50. Aneroid, after Naudet. F., 2nd part, page 35. 



51. Aneroid, after Goldschmidt. F., 2nd part, page 49. 



The foregoing illustrations are selected from the following publications by 

 Dr. Tinter: 



A. Lectures on elementary geodesy (autobiographies). 



A 1 . Lectures on the theory and practice of geodetical and astronomical 

 instruments. 



B. Mathematical, geodetical, and astronomical instruments (History of 

 Trades and Manufactures and Inventions, 1873). 



C. The perspective index, especially with regard to the construction given 

 to this instrument by G. Starke. 



D. The micrometer. 



E. Universal Exhibition Report on astronomical and geodetical instruments. 



F. Lectures on elementary geodesy, Part II. 



