Toposcope


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Toposcope 

1. An instrument for measuring the curvature of the surfaces of a contact lens, based on moiré fringes. A bar pattern is reflected from the lens surface and the reflected image is viewed with a microscope that has a second bar pattern in the eyepiece. The two bar patterns superimposing each other at slightly different orientations create the moiré patterns. The magnification of the microscope is changed until the fringes are parallel to the central index line seen in the field and a dial monitoring this change in magnification indicates the radius of curvature in millimetres.
2. See non-invasive break-up time test. See back optic zone radius; radiuscope.
References in periodicals archive ?
ere's a toposcope - a circular plaque showing the direction and distance to nearby landmarks - at the summit of Beacon Hill, installed to honour the Cadbury family giving the land to the city of Birmingham in 1907.
From this Priory Gateway office (which he eventually took over in 1908) Troyte designed many of the area's most impressive edifices, of which perhaps the best-known is the Toposcope erected on the summit of the Worcestershire Beacon, high in the Malvern Hills.
A small obelisk marks the highest point of this part of Cleeve Hill - the highest point overall is actually on the other side of the radio masts, but the view isn't great - and a handy toposcope helps with navigating the view.
There's a magnificent view, too, across the neighbouring countryside and even better from a local toposcope which overlooks five counties.
A toposcope is perched on top in a mini castle built to celebrate the fact the hill was donated to the city by the Cadbury family in 1907.
And you can see for miles from Oaklands Rec in Yardley, the Toposcope at Beacon Hill in the Lickeys, from the Clent Hills and Barr Beacon's War Memorial.
The very summit is identified by a triangulation plinth and a toposcope to identify the features of the surrounding landscape.
Walk past a triangulation plinth and continue to the toposcope to identify the surrounding hills before returning to the car parkCotswold Wardens' Town walks: PhoneAnn Colcombe 01386 832131
There's also a visitor centre, cafe and a great panoramic view from the toposcope on Beacon Hill.
The metal toposcope at the top of Worcestershire Beacon went missing some time between August 31 and lunchtime on September 1.