Svojstva Metallov (Russian, Paperback)

Nauchno-populyarnaya biblioteka. Vypusk 40. Svojstva metallov. Bylo vremya, kogda dlya izgotovleniya orudij proizvodstva chelovek ispol'zoval tol'ko takie materialy, kotorye davala emu priroda v gotovom vide: derevo, glinu, kamni. Privyazannyj k palke kamen' sluzhil molotkom, iz gliny chelovek delal posudu, iz dereva - domashnyuyu utvar' i t. d. Etot period razvitiya chelovecheskogo obschestva nazvan "kamennym vekom." Pervye metally, kotorymi stal pol'zovat'sya chelovek, byli med' i zoloto; oni vstrechayutsya v prirode v samorodnom vide. No zoloto - redkij i nedostatochno tvyordyj metall. Poetomu osnovnym materialom dlya izgotovleniya razlichnyh orudij yavlyalas' med'. Pozdnee vyyasnilos', chto med' stanovitsya bolee tvyordoj i bolee prigodnoj dlya lit'ya, esli eyo splavit' s olovom. Tak poyavilsya pervyj splav - bronza... This book, "Svojstva metallov," by D. O. Slavin, is a replication of a book originally published before 1952. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible.