john d hamaker : definition of john d hamaker and synonyms
Rock grinders. Hamaker invented an autogenous rock grinder, designed to grind rock upon rock with minimal wear of metal parts, and a macro version, both for creating rock dust. The full design for the rock grinder was described in The Survival Of Civilization and Donald Weaver''s To Love And Regenerate The Earth. On 19 October 1984, China''s Research Institute of Forests accepted a copy of Hamaker''s rock