Ludwig Tesdorpf, Stuttgart. 131 



No. 5. Compass Theodolite with Repeating Arrangement, 

 Horizontal circle 15 centimeter diameter. With hood and glass covering. 

 Divided on argentan in 1/6, reading by 2 verniers to 10". Vertical 

 circle of 12 centimeter diameter, divided in 1/3, reading by 2 verniers 

 to 20". Compass with needle of 10 centimeter length, dial divided 

 in Vi - Telescope with 2 oculars (1 orthoscopic, 1 inverting for zenith 

 readings) with 2 sun -shades. Magnifying 24 times. Alhidada level on 

 the horizontal circle. Pillar level, alhidada- level for the vertical circle- 

 with micrometer adjustment; telescope -level. Case and English model 

 stand, lamp for illuminating the cross -hairs; distance measuring scale* 

 1:100. Tripod with Tesdorpf's horizontal adjustment. 



No. 6. Cofnpass Theodolite. Travelling theodolite, similar to 

 No. 4. Horizontal circle of 10 centimeter diameter, divided in 1/2 r 

 reading to 1 minute; vertical circle of 8 centimeter diameter, divided in 

 1/2, reading to 1 minute. Compass needle of 4.5 centimeter length; 

 dial divided in 1/1 ; 2 oculars; telescope magnifying 20 times; lamp. 

 Patent horizontal adjustment. Case and stand. (See Fig. 2.) 



No. 7. Small Travelling Theodolite. Tachymeter - theodolite. 

 Divisions on argentan. Both circles of 8 centimeter opening, divided in 

 1/2, reading to 1 minute, or 30" by estimation. Telescope magnifying; 

 21 times with objective of 20 millimeter diameter. Box bubble; pillar,, 

 telescope and striding levels. Detachable Compass with parallel ruler; 

 length of needle 7 centimeter. Patent horizontal adjustment. Case and 

 English model stand. 



No. 8. Precision Levelling Instrument. Telescope with hard 

 cast rings resting upon carneol prisms, magnifying 36 times ; orthoscopic 

 ocular. Centering objective. Horizontal clamp with fine adjustment. 

 Elevation screw for conveniently and quickly adjusting the reversion level 

 (of 6 sec. sensibility) attached to the side of the instrument. Tripod 

 horizontal adjustment. (See Fig. 6.) 



No. 9. Patent Precision Levelling Instrument. Telescope with 

 hard cast rings resting on carneol prisms. Magnifying 24 times. The 

 reversion level (Sensibility 6 10"), which is visible in the ocular field, 

 is protected from heat, sun-light or other extraneous influences 

 in general by metal hoods fitted with ground glass windows; these allow 

 the level to be illuminated in a manner which is most pleasant to the 

 eye. By throwing the hoods back the level may be used in the ordinary 

 way. Mounted upon Patent horizontal adjustment. (See Fig. 8.) 



Note respecting Nos. 8 and 9: These instruments, fitted with re- 

 version-levels, have, as compared with other designs fitted with de- 

 tachable or reversible levels, the important advantage that they dispense 

 with the inconvenience of adjusting the level, also with the reversion of 

 the telescope in its bearings. 



These instruments, which are intended for most accurate measurements, 

 can be used without preliminary careful adjustment. The manipulation is sim- 

 plified in the same degree that the accuracy is increased. The manipulations 

 consist in: Adjustment of the level: position I (level on the left); rotation of 

 the telescope in its bearings through 180; second adjustment of the level: 

 position II (level on the right). " 



9* 



