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Lot Essay
Charles Howorth was a barometer maker who specialised in making angle tube barometers. An example of his work in the Bolling Hall Museum, Bradford has a type-written note on the back stating that Howorth lived at Ireland Farm, near Shibden Industrial School, Halifax. It also quotes an interesting extract from the diary of a Miss Lister of Shibden Hall;
Friday, February 28th 1823. Charles Howorth told me the barometer stands 6½ degrees lower at the top of Clayton heights than here and he reckoned for each degree 30 yeards of perpendicular height in making his barometers. He divides his scale (I-think he said) into four parts, the lowest degree being 28 inches height of the mercury and the highest at 31 inches.
The inventor of the angle tube is unknown but it is traditionally thought to have been Sir Samuel Morland (1625-1696). In a straight tube the mercury moves only a very short distance. If the tube is bent just beneath the lowest point to which the mercury can fall and then extended at an angle the mercury will move over a far greater distance.
Friday, February 28th 1823. Charles Howorth told me the barometer stands 6½ degrees lower at the top of Clayton heights than here and he reckoned for each degree 30 yeards of perpendicular height in making his barometers. He divides his scale (I-think he said) into four parts, the lowest degree being 28 inches height of the mercury and the highest at 31 inches.
The inventor of the angle tube is unknown but it is traditionally thought to have been Sir Samuel Morland (1625-1696). In a straight tube the mercury moves only a very short distance. If the tube is bent just beneath the lowest point to which the mercury can fall and then extended at an angle the mercury will move over a far greater distance.