THK TRANSIT 



35 Showing general equipment with Vertical Clamp, Telescope 

 Bubble and Vertical Arc, covered under the No. 043 4-in., 

 No. 053 5-in. and No. 063 6-iii. Transit. 



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Ill TRANSIT is an instrument made use of by opera- 

 tive engineers to project alignments, to observe or lay- 

 out angles in the horizontal or vertical plane, to 

 estimate distances, establish grades, run levels and 

 erect perpendiculars. 



It is made up essentially of three component 

 parts; the leveling base, which contains the outer 

 socket of the compound center, the graduated hori- 

 zontal plate which is mounted on an intermediate sock- 

 et known as the azimuth axis, and the alidade, carrying the vernier 

 scales, the standards, the telescope and vertical limb, which is mount- 

 ed on an inner spindle known as the vertical axis. The com- 

 pound centers are, therefore, more or less intimately related to 

 every working portion of the instrument. The graduated circles 

 have been aptly designated as the "brain" and a similitude has been 

 drawn between the telescope and the "soul" of the instrument, but the 

 compound centers are the constitution in which all of the organic 

 t adjustment and operation have their origin. 





