Abstract: |
A de Saussure's hygrometer by Richer, marked 'Richer breveté du Roi N° 10'. Similarly on the upright, although only 'du Roi' is visible, but here is inscribed also 'a Paris 1788'. Circular disc reads from 0 to 100, marked every ten divisions as 10, 20, 30, etc.. Also marked 'Sec' near 0 and 'Humide' near 100. The thermometer (bulb broken) has Réaumur scale (from -20 to 80) on right and Fahrenheit (from -10 to 212) on left. Brass mounting on two tired wooden base with feet. |