{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"A Treatise On Mathematical Instruments: Including Most of the Instruments Employed in Drawing, for Assisting the Vision, in Surveying and Levelling, ... and for Measuring the Angles of Crystals...","author_name":"John F. Heather,","thumbnail_url":"https://www.ebooknetworking.net/books/B00/AOB/bigB00AOBJ9FW.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-B00AOBJ9FW.html\">A Treatise On Mathematical Instruments: Including Most of the Instruments Employed in Drawing, for Assisting the Vision, in Surveying and Levelling, ... and for Measuring the Angles of Crystals...</a>","width":400,"height":300}