193

The chief feature of this instrument is the fact that the frame supporting the telescope is cranked so that the telescope can be moved through 90° either side of the vertical, thus enabling a bearing to be taken of any object upon the surface from the top of the shaft and a line sighted at the bottom of the shaft in the same vertical plane with it, without changing the horizontal adjustment of the instrument. The vertical arc is divided to read single minutes. The telescope is fitted with stadia points for reading distances without the use of a chain.

10. Combined Altitude Instrument and Prismatie Compass. (Fig.12.)

With this instrument altitudes, levels, horizontal angles, compass bearings, and rise and fall of any surface in degrees or millimetres per metre can be obtained. The diameters of the compass dial and altitude circle are 63 mm., both being divided into half degrees. The altitude circle has also a scale of rise and fall in inches per yard or millimetres per metre.

ci £

11. Improved Sight or Surveying Compass and Clinometer. (Fig. 13.)

This instrument is fitted with simple and yet efficient sights. To convert the instrument from a surveying compass into a clinometer for taking vertical angles or levels it is only necessary to move the sights through 90°, when both sights and compass can be used for levels or inclination.

4 4240. N

---

Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour cette page est de 99,27 %.

La langue de reconnaissance de l'OCR est l'Anglais.

---