div class=ts-pagebuttonPage 1button div class=ts-image amp-img class=ts-thumb alt=Page 1: An Introductory Course of Mechanics src=https:reader031vdocumentsmxreader031viewer2022020405575067d01a28ab0f07ad45f1html5thumbnails1jpg width=142 height=106 layout=responsive amp-img divp© 1934 Nature Publishing Grouppdiv