thermoscopes

Of all substances that we are acquainted with, the one which most readily receives and loses heat is air; as is best seen in calendar glasses [air thermoscopes], which are made thus.

The New Organon 2005

If we make the experiment with two such thermoscopes we at once become aware of something which usually escapes us, our attention being fixed on the figures recorded by the two instruments.

Man or Matter Ernst Lehrs

Other thermoscopes may give even larger indications; but meanwhile the

Moon Lore Timothy Harley

Although the various thermoscopes for air or liquid used in the very beginning admitted of only arbitrary graduation, they nevertheless served to indicate the constancy of the temperature or the direction of its variations, and consequently contributed to the discovery of a number of the laws of physics.

The Catholic Encyclopedia, Volume 12: Philip II-Reuss 1840-1916 1913