{"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,","author_name":"John Fry Heather","thumbnail_url":"https://www.ebooknetworking.net/books/129/688/big1296883418.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-1296883418.html\">A   Treatise on Mathematical Instruments: Including Most of the Instruments Employed in Drawing, for Assisting the Vision, in Surveying and Levelling,</a>","width":400,"height":300}