Accession No
0895
Brief Description
pocket weather forecaster dial, by Negretti and Zambra, English, 1/2 20th Century
Origin
England; London
Maker
Negretti and Zambra
Class
meteorology
Earliest Date
1900
Latest Date
1939
Inscription Date
Material
plastic; paper; metal (steel)
Dimensions
diameter 55mm
Special Collection
Robert Whipple collection
Provenance
Bought by Robert Stewart Whipple in 06/1939.
Inscription
‘NEGRETTI & ZAMBRA. LONDON’ (lowest disc)
Description Notes
Pocket weather forecaster dial, by Negretti and Zambra, English, 1/2 20th century.
Three plastic discs of diminishing diameter. Lowest marked with wind direction. Middle with barometer readings from 28 - 31 (inches). Upper with three windows for ‘Rising’, ‘Falling’ and ‘Steady’ state of the Barometer. Reverse engraved with forecasts corresponding to letter of alphabet read in window of centre disc.
Cardboard box with set of instructions.
Good condition, paper case shows some wear.
References
Allison Ksiazkiewicz; 'Weather Forecasting'; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge: https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/weather-forecasting
Events
Description
This pocket weather forecaster was intended to be used in conjunction with a barometer and weather vane.
The three discs are set by the user to show the present wind direction, the barometer reading (from 28 to 31 inches) and the barometer’s tendency (whether it is rising or falling). A letter then appears in the central window, which corresponds to one of the forecasts engraved on the reverse of the discs.
The booklet that accompanied the forecaster gives directions for its use:
1. Using both thumbs, rotate both discs so that the arrow marked ‘Set Wind’ matches the wind direction
2. Hold the middle disc fixed; with the left thumb
3. Rotate the front disc with the first and second right-hand fingers, so that the arrow marked ‘Set to Barometer Reading’ agrees with the barometer reading set for sea level.
4. Read the code letters in the windows for a ‘Falling’, ‘Steady’ or ‘Rising’ barometer and refer to the back of the forecaster for the interpretation.
The letters ‘S’ for Summer (April to September) and ‘W’ for Winter (October to March) refer to the time of year. The forecast is for 12 hours and the best time to take a forecast is 9 am.
26/03/2008
Created by: Dr. Anita McConnell on 26/03/2008
FM:39891
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