Abstract: |
Cylindrical glass vessel on brass base fitted with tap and containing barometer tube fitted to brass support (graduated). Vessel tapers very slightly upwars. The brass scale attached to the barometer is graduated from 1 to 20 on both sides. Between each large graduation, three other numbers are marked, 3, 6, 9, and the interval between each is divided into six parts, and thus each large unit is divided into twenty-four parts. A sliding vernier is also attached. Lower end of tube is rounded to shape of inverted cup. |