Год выпуска: 2010 Автор: Alexander Ross Clarke Издательство: Страниц: 372 ISBN: 1440088659
Описание
CHAPTER 1.GEODETICAL OPERATIONS.0.1-' the many discoveries made in modern times by mcn ofseience-astronomcl's and travellers-none have cver tendedto shake the doctrjne held and taught by the philosophers ofancient times that the earth is spherical. That the surface ofthe sea is convex anyone may assure himself by simply observing,say with a telescope from the top of a cliff ncar the sea,the appearance of a ship on or near the horizon, and thenrepeating a few moments after at the foot of the cliff thesame observation on the same ship. Assuming the earth tobe a sphere, a single observation of a more precise naturetaken at the top of the cliff would give a value of the radiusof the sphere. The 0bservation required is the dip or angleof' depression of the horizon: this, combined with one linearmeasure, namely, the height of the cliff, will suffice for arough approximation. This is an experiment that was madeat ~rount Edgecombe mOl'e than two centuries Table of Contents Geodetical...
