Graticules Ltd. Model S-7 England Finder Slide
The England Finder is a glass slide marked in vacuum deposited chromium over the top surface in such a way that a referenced position can be directly read relative to the locating edges.
All England Finders produced by Graticules Ltd. for over 40 years are identical. The purpose of the finder is to give the microscopist an easy method of recording the position of a particular field of interest, so that the same position can be re-located at a later date, or by another person in another laboratory, or when using any other England Finder on any other microscope. The repeating distance of the pattern of this unique slide is approximately 1mm, but it is not precisely 1mm, and the slide is designed as a reference tool and not as a calibration artifact. It should not be used to calibrate magnification or stage travel.
The location of the arrows is identical for all England Finder slides. Mark a label on the left hand side of the specimen slide, indicating the orientation to be repeated. By replacing the specimen slide with the England Finder, taking care not to disturb the position, the feature of interest can be noted. The feature can also be re-located at another place or time by reversing the procedure. Hundreds of positions on a 76mm x 26mm slide can be accurately located.