for the dial is furnished by two 21/½ volt screw type lamps (Mazda 14) which are mounted in the clear plastic ring which
encircles the dial and diffuses the light evenly. Energy for the lamps is provide(d by two size D flashlight batteries which
are housed in a separate container inside the case. The lamps and batteries can easily be replaced by removing the
screw plugs in the side of the case. The intensity of light can be regulated by the rheostat an(d switch located on the side
of the case. The cover contains the storage space for the accessories.
The mechanism contains the pressure sensing element (1, fig. 4), the linkage, and the pointer. The pressure
sensing element is a capsule which is sensitive to changes in atmospheric pressure. Movement of the capsule is
transmitted to the pointer through a linkage consisting of the actuating rod (2), support bracket and gear sector assembly
(3), pinion, and pointer shaft.
The accessories, which are mounted in the cover, consist of a pocket magnifier (3, fig. 5), a psychrometer assembly (5), a
spanner wrench (4) for tightening the caps, a container of spare psychrometer wicks (9), a spare pointer in a container (7),
two spare lamps (8), two sets of correction and conversion tables furnished on 6 x 4 cards (3), and a wiring diagram of the