An Improved Levelling or Surveying Instrument.

摘要

1144. Petrini, P. Jan. 15. Theodolites.-A telescope 12 and level 13 are carried by means of straps 11 upon a tube 10, which is mounted upon a square part of an arbor 1 connected with a wheel-train indicator graduated to indicate rise or fall in metres per 100 metres. An index 8 with a compass 9 indicates on a graduated disk 6 the movements in azimuth of the telescope and level.