nished, divided 0°- 360° by 10'. Four verniers (I, II, III, IV), divided
0 '-1 0 'b y l0 " . Clamp and fine adjustment at side, pair of microscopes
with card holders to read verniers.
Magnetometer-, instrument for measuring terrestrial magnetic for^-
This demounts from a circular brass base, and fits onto centre of the
main instrument, replacing the dip-circle. It has two scales (diameter
96), divided 0° - 80” by 15'. Magnet supported in a cradle held by a filar
in a long brass tube with adjustment scale at the top. Overall height-410.
Declinometer: the magnetometer arrangement is' altered using some of
the items amongst the accessories listed below. A plane mirror illuminates
the chamber holding the magnet.
Theodolite: mounted to one side of the base circle; scale (diameter 108)
is bright, divided 0” - 360” by 15). Two verniers (I, II) O’ - 15' by 20".
Two reading microscopes with reflector frames; telescope aperture
20mm. Eyepiece has cross wire and a prism to view when near vertical.
Graduated bubble level and removable bubble level that fits over the
top of the trunnions.
Accessories
1< Two brass tubes, marked 1 and 2, fit on marked projections;
each has two holes, marked 0 and 80; 560 and 640; length
p 270, diameter 13.
2. Two sections of black-painted brass to protect scale on magnetometer.
3. Mahogany box in two parts with portholes in each end; ends
painted black; circular slot to hold thermometer at one side;
intended to fit around cradle on magnetometer. Mercury thermometer
5”- 38° by 30', in a marbled-paper tube.
4. Wooden box with sliding lid, containing a steel needle (length
149), marked at ends: All; BII. Also space for a smaller steel
needle (in box 5), Also brass tweezers, black (ebonite) support
to fit on the side tubes; eyepiece for transit telescope with
right-angled prism and shade.
Wayorateui'a
lagnalinchBH Umvorsnlinslrument