The Works of John Playfair Volume 2

The Works of John Playfair Volume 2

List price: US$9.77

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks


This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1822 edition. Excerpt: ...he could publish the result. Muschenbroek, who calculated the whole anew from his papers, came to the conclusion just mentioned, which, of course, was not known till long after the time when the measure was executed. No advantage, accordingly, was derived to the world from this measurement till its value was lost in that of other measurements still more accurately conducted. A computation which, for the time, deserves considerable praise, is that of Norwood, in 1635, who measured the distance between London and York, taking the bearings as he proceeded along the road, and reducing all to the direction of the meridian, and to the horizontal plane. The difference of latitude he found, by observation of the solstices, to be 2 28', and from that and his measured distance, he concluded the degree to be 367,176 feet English, or 57,800 toises. This has been found to be a near approximation; yet his method was not capable of great accuracy, nor did he always execute it in the best manner. "Sometimes," says he, "I measured, sometimes I paced, and I believe I am within a, scantling of the truth." Feme!, a French physician, measured with a wheel from Paris to Amiens, which aro nearly in the same meridian, and he determined the degree from thence to be 56,746 French toises; a result which falls short of the truth, though not very considerably. These investigations, it is plain, could not but leave considerable uncertainty with respect to the magnitude of the earth. The Academy of Sciences became interested in the question, and the measurement of an arch in the meridian was undertaken under its auspices, and executed by the Abbe Picard, already known for bis skill in the operations of practical geometry. He followed a method...
show more

Product details

  • Paperback | 100 pages
  • 189 x 246 x 5mm | 195g
  • United States
  • English
  • black & white illustrations
  • 1236934172
  • 9781236934178