00402cam a2200169 a 4500001000800000005001700008008004100025010001700066040001800083041000800101080001500109082001900124100000700143101000800150245005600158740001800214375155720180123072106.0821213r1983    ctua   j d    001 0 eng    a   82019610   aDLCcDLCdDLC  aeng  a603.21 STU00a603.21 STU219  a23  aENC14aThe illustrated science and invention encyclopedia.0 aHow it works.