The classic how-to book of binocular astronomy by Philip Harrington. Explains what you need to know about buying and using binoculars. This book is an excellent manual and field guide for amateur astronomers. Contains a catalog of over 1,000 objects visible in binoculars. 7x50 binoculars are exactly the mid-point from naked eye to a 20" telescope. Softbound very good condition. $15 shipped CONUS USPS Priority Mail. PayPal, MO, cleared check.