Davis Derby Instruments

 

 

Davis Derby produced various types of Clinometers and angle finders as early as 1860.

 

There is evidence that the Abney level similar to this type appeared in a 1902 catalogue.

 

 

 

 

 

Figure 1 Abneyís Level

 

Davis Derby produced air powered lamps from the 1920ís up to 1988. Versions of this lamp were approved for use in gassy atmospheres and consequently found applications in mines, quarries, sewer work and for tank cleaning operations.
Figure 2 Compressed Air Lamp

 

John Davis announced in the Derby Mercury on February 12th 1845 that Biramís patent anemometer would be ready in a few weeks. Davis Derby produced anemometers based on the Biram patented design from 1845 up to 1960.

 

Various designs were manufactured including pocket versions and self-timing anemometers.

 

 

 

Figure 3 1850 Biramís Anemometer


Anemometers were featured in the companyís catalogue up to the 1950ís, the anemometer business was sold to Negretti and Zambra in the 1950ís

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3 1850 Biramís Anemometer

 

Figure 4 4īī Anemometer and case

 

Figure 5 Anemometer


 

Text Box: Figure 6 Dumpy or Gravett Level (1880)The Dumpy level was used in surveying operations above and below ground. It can be used for some of the applications of the theodolite.

 

The Dumpy level was in production in 1890ís often used on railways, tunnelling and irrigation work.

 

 

 

 

 

In 1850 John Hedley, one of H.M. Inspectors of Mines, being convinced of the inconvenience of miners' compasses and dials then in vogue, collaborated with John Davis (the founder of the firm), and the Hedley Dial was evolved John Davis included a Hedley dial in his 1860 price list. The price was £7:10:00.


Figure 7 Hedley Dial (1930)

The company introduced many improvements over the years and continued to produce Hedley dials up to the 1950ís

 

The Hedley dial is designed for levelling and direction finding.
Figure 8 Hedley Dial (1930)

John Davis was fascinated by surveying instruments and these were included in the 1860 price list, but were known to be in production prior to that date. The theodolite was used for surveying and levelling operations in mines and quarries.

 

 

 

 

 

 

Fig 9 Theodolite in Case

 

 

 

 

This particular model was manufactured in 1866, theodolites were manufactured up to the late 1950ís
Figure 10 Theodolite 1866

 

Davis Derby produced various types of wet and dry thermometers, (Hygrometers). These devices were in manufacture from the mid nineteenth century. They were listed in the 1860 price list and were included in catalogues in the 20th century. The version shown here is a hand held device which is designed to swung like a football rattle.

 

 

Figure 11 Edney Swing Hygrometer

 

 

 

Little is known about the Hydrogen tester, but it was used for testing air balloons

 

 

 

 

 

 

Figure 12 Hydrogen Tester

 

 

 

Davis Electric lamps were produced from around 1920 and were still in production around 1945
Figure 13 Davis Electric Lamp

Figure 14 Davis Derby Hand Lamp


 

Figure 15 Little Demon Exploder


Figure 15 Evershedís Portable Ohmmeter

 

During World War 2, Davis Derby undertook essential war work and produced various instruments including altimeters for Wellington bombers.

 

 

 

 

 

 

Figure 16 Altimeter for the Wellington Bomber

The Kirkby 2A Haydock lamp was in production in 1940 (and probably for many years before that). The lamp which was described as being ďof large candle-power and convenient in size and weight.

Figure 17 Davis Kirkby 2A Haydock Lamp

Figure 18 Davis Kirkby Lamp