Inclining dial
Inclining dial for latitudes 0°-52° North. This dial consists of a silver base-plate and a hinged hour-plate. The base-plate carries a brass compass with no points marked. A brass rod passes across the diameter of the compass and out of the bottom edge where it ends in an arrow that moves over a magnetic variation scale. The compass can move to allow the magnetic variation to be altered and it is locked in position by a brass screw in the north-east corner. Hinged to the south-east corner of the base-plate and passing through a hole in the hour-plate is the latitude scale, numbered 0-52°. There is a table of latitudes on the reverse side of the base-plate comprising towns and cities in Europe. The hour-plate has a central circular hole to allow the compass to be viewed. There are two holes on the Meridian line where the gnomon once stood. The dial is signed 'Cadran Universel et a Merine Fait et jnventé par julien le Roy de la Societé des Arts'.
It is presumably this form of inclining dial that Le Roy claims to have invented, since the general principles of such instruments were known before and had been discussed in books on dialling (such as Nicolas Bion's 'Traite de la construction et des principaux usages des instrumens de mathematique' of 1709). The latitudes numbered on the latitude scale all lie within Europe and the northern Mediterranean apart from 23°. A similar dial in the MHS, Oxford (new inventory no. 53108) is complete with its gnomon support and string gnomon (missing from the present example).
For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.
It is presumably this form of inclining dial that Le Roy claims to have invented, since the general principles of such instruments were known before and had been discussed in books on dialling (such as Nicolas Bion's 'Traite de la construction et des principaux usages des instrumens de mathematique' of 1709). The latitudes numbered on the latitude scale all lie within Europe and the northern Mediterranean apart from 23°. A similar dial in the MHS, Oxford (new inventory no. 53108) is complete with its gnomon support and string gnomon (missing from the present example).
For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.
For more information about using images from our Collection, please contact RMG Images.
Object Details
ID: | AST0522 |
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Collection: | Astronomical and navigational instruments |
Type: | Inclining dial |
Display location: | Not on display |
Creator: | Roy, Julien Le |
Date made: | Early to mid 18th century |
Credit: | National Maritime Museum, Greenwich, London, Caird Collection |
Measurements: | Overall: 17 x 59 x 82 mm |