Newcomb, Simon, 1835-1909, Holden, Edward Singleton, 1846-1914, joint author · New York, H. Holt · leaf 143
ay aday or a week, moves from P^ to P%. At another partof its orbit it moves from P to Pt in the same time,and at a third part from P4 to Pb. Then the areasSP,P„ SPP„ SP,Pb will all be equal. A littlegeometrical consideration will, in fact, make it clear thatthe areas of the triangles are equal… … Fig. 51.—law of areas. In the time of Kepler the means of measuring thesuns angular diameter were so imperfect that the preced-ing method of determining the path of the earth aroundthe sun could not be applied. It was by a study of themotions of the planet Mars, as observed by Tycho Brahe,that…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from M. Vitrvvii De architectvra libri decem : nuper maxima diligentia castigati atq[ue] excusi : additis Iulij Frontini De aqueductibus libris propter materiae affinitatem (1522)](https://img.insideoutlibrary.com/img/200/ia-mvitrvviidearchi00vitr-206-82.webp)