The Photogrammetric Society Analogue Instrument Project: A Fifth Extract

The paper entitled The Photogrammetric Society Analogue Instrument Project was published in The Photogrammetric Record, 14(82): 565-582 and contained, as Appendix A, an extract from the Archive concerned with the history of the Zeiss Stereoplanigraph in Great Britain. A further three extracts have since been published to provide details of direct optical projection instruments used in this country and of the Vivian Thompson Stereo-plotter.
This fifth extract deals with the Wild A5 and A6 instruments. Their introduction into the United Kingdom during and just prior to the Second World War, together with their important contributions to the war effort, make interesting reading. With a grand total of just five such instruments, they were well used throughout the period of hostilities.
This extract also includes a note on the Wild A4 instrument, designed for close range photogrammetry. This was the last instrument in which Wild made use of projector lenses but it has been included at this point so that all of the Wild instruments which are listed in the Catalogue (and therefore included in the Archive) are dealt with in numerical order.