From the history of surveying instruments

"The Dioptra " written by Heron contained a most interesting description of surveying instruments called the Diopter, one of the first surveying instruments of which we have record. The work of Heron was the authority for a great many years among Greek and Egyptian surveyors.

The Romans developed some most ingenious instruments which produced remarkable results. Among these were the Groma used for sighting; the Libela, an A-frame with plumb bobs used for leveling and Chorobates,a horizontal "straight-edge" about twenty feet long with supporting legs and a groove on top for water to act as a level. Previous to the sixteenth century surveying has been treated as practical geometry, but with its rise as a profession, the books gained the title of surveying, although they included much elementary geometry. In the sixteenth and seventeenth centuries a few books were published, some of which are in existence today.

They included a good deal of geometry and elementary mathematics and gave and an insight into the field methods of surveying was used in those early days. They also described surveying instrument, including the Circumferentor, Theodolite, Plane Table, Water Level, Sextant, Chain, and Perambulator.

In the seventeenth century surveys to determine length of are of earth's surface brought forth the use of accurate instruments to measure angles. This led to the first theodolite using a full horizontal circle of 360 made by Diggs in 1571. The first really precise instrument was made by Romaden in 1783. The divisions on this instrument were made by an accurate dividing engine, and it was the forerunner of the transit in use today.

2. Answer the following questions:

1. What was the first surveying instrument?
2. Who made the first records about surveying instruments?
3. What happened in the 16 century?
4. Who invented the first theodolite using a full horizontal circle?
5. When was the first theodolite using an accurate dividing engine invented?

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