{"product_id":"g-jermain-porter-a-catalog-of-4683-stars-for-the-epoch-1900-classic-reprint-9780366908134","title":"A Catalog of 4683 Stars for the Epoch 1900 (Classic Reprint)","description":"Excerpt from A Catalog of 4683 Stars for the Epoch 1900\u0026lt;br\/\u0026gt;\u0026lt;br\/\u0026gt;The transit observations made with the Gaertner micrometer in the prosecution of this work were recorded on the chronograph with a hand key. The micrometer described in Publication 13 as in use prior to December, 1914. Instead, however, of using the lines ruled on glass, as there described. Five vertical spider wires were mounted in the reticle and used. Thus all the transit observations made in the preparation of this volume were recorded with a hand key, and, except for an occasional broken transit, five wires were used throughout.","brand":"Forgotten Books","offers":[{"title":"Default Title","offer_id":53752101273942,"sku":null,"price":0.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0925\/5829\/5382\/files\/product_image_9780366908134_1_1735c259-6d2f-4475-845c-75092d721acb.jpg?v=1781793387","url":"https:\/\/www.momoxbooks.com\/products\/g-jermain-porter-a-catalog-of-4683-stars-for-the-epoch-1900-classic-reprint-9780366908134","provider":"momoxbooks","version":"1.0","type":"link"}