Your hair hygrometer may not actually be this accurate, but it can give you a rough approximation of changes in humidity.

How similar are the readings between your hair hygrometer and these precise instruments?

It is of interest here to record that at the moment of writing a series of experiments are in progress in which an attempt is being made to use a hair hygrometer for this purpose.

The mean annual temperature of the valleys of Aragua is nearly 25.5 degrees; my hygrometrical observations of the month of February, taking the mean of day and night, gave 71.4 degrees of the hair hygrometer.

"A hair hygrometer," he said to me, waving his wax-like hand over it.