Founded in 1880 at 109 Deansgate, Manchester by Alexander George Thornton, the firm grew to become one of the largest manufacturers of drawing instruments and slide rules in Britain. The Precision Instrument Co was taken over in 1901 and PIC continued to be used by Thornton as a trade mark until about 1970. The firm became British Thornton in 1967 and merged with ESF at Burley in 1992. British Thornton is now a manufacturer of school furniture in Keighley.
A traditional pattern set of electrum instruments by A G Thornton dating from the late nineteenth century.
The instruments were purchased loose and I adapted an empty steel case to take them by making a set of velvet lined pockets to fit the instrument tray of the case in the same way as they would have originally been made.
A six inch circular protractor by Thornton of Manchester. This copper alloy protractor is probably gun metal but could be brass. About 1900.
A "British Empire" pattern set, dated 1939, made for H M Government.
This pattern of instruments was basically that “approved by the Inter-Departmental Committee appointed to consider the design of British drawing instruments” (ref: Casella catalogue no. 564 p173). They were made with minor variations by several British manufacturers.
A "Minerva Series" set in a large 'pocket' case. Thornton introduced the Minerva series prior to 1916 (they appear in the catalogue for that year) and continued making them until, at least, the 1950s.
The section Miscellanea (Who Made Them) features a Halden Premier set in which the metal instruments are of the Minerva series pattern. It is highly probable that Thornton made the electrum instruments for the Halden Premier sets as they were better quality than Halden’s own manufacture.
A Thornton Minerva set in a tropical case. Besides the usual instruments the tray contains a drop bow compass.
The bottom of the case contains celluloid curves, a protractor and a Thornton Kinwest six-inch adjustable set square.
Another Thornton Minerva set in a tropical case. This one includes a celluloid clinograph.
Thornton Techset instruments in a wallet case. The Techset series were a cheaper version for students, based closely on the Minerva series.
A small case of Techset instruments. The compass and dividers are smaller size instruments.
The Jaywess series of instruments, made by Thornton, were their cheapest range, aimed at technical schools.
A small Jaywess set. The turnabout spring bow did not feature in their more expensive sets but was common in Jaywess ones.
This eight inch "Thornton PIC" adjustable set square was purchased by me as a student in 1963 and the transparent part is acrylic. It is still in use when a square is needed.
A set of British Thornton instruments dating from about 1970. It includes large and small spring bows, a beam compass, dividers and a drop bow (or rotating) compass. The instruments are housed in plastic foam (which has been replaced as the original had perished to dust) instead of velvet lined pockets. The instruments would probably have been selected and then the appropriate size case purchased to house them.
VC7983 Compasses, Beam, 26” T.P. (Thornton Pattern) B8025. Roller beam compass, presumably by A G Thornton, patent number 155970/19. A set of beam compass fittings made for the WD in the mid twentieth century. Brass and steel. One of the long steel points would be clamped to one end of the beam by the smaller fitting (top left). The larger fitting (top right) has a spring at one end and a roller at the other. The insert holder (bottom right) fits into this fitting and either the pen, pencil or needle point insert can be fitted in this.
This type of beam compass (but nickel silver) is shown in the 1930 B J Hall catalogue where it is described as “Gill’s Patent no. 155970/19”.
Set of electrum and steel spring bows, probably Edwardian. Unusually they have hexagonal handles and centre thumb wheels. The pen & pencil bows are fitted with Thornton’s Improved Nut & Bolt points (Rd. No. 354,874), whilst the divider bow has plain points. Morocco covered, blue silk & velvet lined case.
Ministry of Works set no. 5136 made by A G Thornton in the mid-20th century. The instruments are based on the Techset series but appear to be made of a light coloured brass rather than electrum. The pen handles are ivorine, as is the Protractor Rectangular 6 inch Ivorine A Mk IV. The parallel rule is boxwood. This set is of a type made by several manufacturers to what appears to be a government specification.
British Empire pattern set made for the British government in 1938. Oddly, not all the instruments are signed Thornton. The large compass, dividers, bow compasses and parallel rule are marked Harling and the protactor is by GH Cooper and dated 1936. The pens are unsigned. There could be a number of reasons for this. This set is higher quality than the MOW set above.