Tuesday, September 19, 2006


Q & A exercise

Read the paragraphs and answer the questions.

Leonard Diggs introduced the word "theodolitus" in his Pantometria (London, 1571). This surveying instrument had a circular ring or plate divided into 360 degrees, and a pivoting alidade with sight vanes at either end. Theodolites of this sort, as well as others with a second pair of sight vanes affixed to the graduated circle, were soon in widespread use. In 1791, George Adams Jr. called this instrument a "common theodolet," reserving the term theodolite for the telescopic instruments with horizontal circles and vertical arcs that had been introduced in London in the 1720s.

1.- Who introduced the word theodolite in a book?

Leonard Diggs introduced the word theodolite in a book

2.- What was the name of the book?

The name of the book is Pantometria

3.- When was the book written?

The book written in 1571

4.- How many degrees was this device divided into?

This device divided into 360º

5.- Who called this device a common theodolet?

George Adams Jr. called this instrument a "common theodolet

6.- Where and when did they introduce the term theodolite?

The term theodolite was introduce in London in the 1571.

They introduced the term theodolite in London in the 1571.

While the telescopic theodolite was popular in England, Americans preferred the surveyor’s compass and, later, the surveyor’s transit, which were cheaper and more robust. In the 18th century form, the telescope is mounted directly on the vertical arc. In the transit theodolite, which originated in London in the 1840s, the telescope is transit mounted, with a vertical circle mounted at one side. Heinrich Wild’s optical theodolite, introduced in Switzerland in the 1920s, had several new features, including an auxiliary telescope that lets the user read either circle without moving away from the station.

1.- Which were cheaper and more robust the surveyor’s compass or the surveyor’s transit?

The surveyor’s transit was cheaper and more robust

2.- What did Heinrich Wild’s do in the 1920’s?

He introduced the optical theodolite.

Some theodolites measure horizontal angles with geodetic accuracy. The first instrument of this sort was made by Jesse Ramsden in London in 1787, and purchased by the Royal Society for use on the geodetic link between Greenwich and Paris. The first instrument of this sort in America was made around 1815 by Troughton in London for the fledgling United States Coast Survey.

1.- What does “geodetic” mean?

Geodetic was World System defines a fixed global reference frame for the Earth, for use in geodesy and navigation.

2.- Who purchased Jesse Ramsden’s device?

The device of Ramsden was purchased by the royal society.


Geodesy is primarily concerned with positioning and the gravity field and geometrical aspects of their temporal variations, although it can also include the study of the Earth's magnetic field. Especially in the German speaking world, geodesy is divided in geomensuration, which is concerned with measuring the earth on a global scale, and surveying, which is concerned with measuring parts of the surface.
The shape of the earth is to a large extent the result of its rotation, which causes its equatorial bulge, and the competition of geologic processes such as the collision of plates and of vulcanism, resisted by the earth's gravity field. This applies to the solid surface (orogeny; few mountains are higher than 10 km, few deep sea trenches deeper than that.) Quite simply, a mountain as tall as, for example, 15 km, would develop so much pressure at its base, due to gravity, that the rock there would become plastic, and the mountain would slump back to a height of roughly 10 km in a geologically insignificant time. (On Mars, whose surface gravity is much less, the largest volcano, Olympus Mons, is 27 km high at its peak, a height that could not be maintained on Earth.) Gravity similarly affects the liquid surface (dynamic sea surface topography) and the earth's atmosphere. For this reason, the study of the Earth's gravity field is seen as a part of geodesy, called physical geodesy

It in the second line refers to: the gravity field and geometrical aspects
Which in the fourth line refers to : geodesy
Its in the seventh line refers to : The shape of the earth
Which in the seventh line refers to : rotation of the earth
This in the ninth line refers to : the earth's gravity field
Its in the seventh line refers to : the base of mountain


  • Where is the "ed-inflection"? I mean, the chart where you have to put the sound of the regular vebrs in past.

    By Blogger ricardo, at 8:06 AM  

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