The prototype commercial HCN gas laser unit consisting of a discharge tube and thermally stabilised optical system capable of giving 1 mW output in the far infra-red range, 1971. prototype HCN infra-red laser 1970-1972
Automatic scale measuring laser interferometer (length comparator) Automatic scale measuring laser interferometer (length comparator) 1964-1965
Taper Thread Gauge checking machine, 1934, for the measurement of the thread pitch. Taper Thread Gauge checking machine circa 1934
Two micrometer surface testers used together and with electric bell system to measure divergence from flatness of large plane surfaces; designed and used by Dr. P.E. Shaw for experimental work in 1911. Micrometer surface testers 1911
Thermal conductivity apparatus for thin discs of insulating materials designed and built at the National Physical Laboratory, England, 1923. Thermal conductivity apparatus 1901-1927
Eden's Screw diameter measuring machine; floating head type, 2" capacity with a pair of 14 t.p.i. needles. Eden's screw diameter measuring machine, 1916 1916
Sir Patrick Moore's first surviving large telescope, nicknamed 'Oscar'. 12 1/2 inch reflecting telescope by H.N. Irving and Son, Teddington, London. Mirror by Wildey, London. Tripod not original. Bought c. 1948 and used at East Grinstead, Armagh and Surrey. Used for lunar observations, including those used by Moore to map libration zones. Acquired alongside the Archive of Sir Patrick Moore. 'Oscar', Sir Patrick Moore's first surviving large telescope circa 1948
2 Bench micrometer-heads from a bench type measuring machine,made 1924, by the N.P.L. 2 Bench micrometer-heads from a bench type measuring machine 1924