{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"A treatise on the principal mathematical instruments employed in surveying, levelling, and astronomy","author_name":"Frederick Walter Simms","thumbnail_url":"https://www.ebooknetworking.net/books/B00/66J/bigB0066J4ZGO.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-B0066J4ZGO.html\">A treatise on the principal mathematical instruments employed in surveying, levelling, and astronomy</a>","width":400,"height":300}