METEOROLOGICAL INSTRUMENTS 14

We add 32° to get the Fahr. reading, 98-6, because in the calcuiatic
we assumed freezing point to be 0 instead of 32°.

Example.—Convert 60° Fahr. into the corresponding Absolute seal
reading.

Assume freezing point Fahr. to be zero then 60—32=28.
Cent, reading Fahr. reading —32
Cent, range Fahr. range

jc___J28^ ^ __ 28x100 _ 140

100""ISO"35 ISO ~ IT ^

+273-0

Ans. 288*5 Abs.

Check those answers by referring to Figure 15.

THE MAXIMUM THERMOMETER.

The maximum thermometer is designed to record the highes
temperature experienced during a given period. The tube is reduce<
in bore about an in?ch from the bulb. The thermometer is hung nearb

Fig. 16.
horizontally with the bulb end slightly lower than the other. Ai
the temperature rises the mercury expands and is forced past* th<
constriction, but, when a subsequent faU of temperature causes *
contraction of the mercury, the thread breaks at the constriction s<
that its upper end remains in position and registers the highest tempera