SCIENTIFIC AMERICAN July 12, 1879. This 16 page issue is in nice condition and contains illustrations of the latest inventions of the day including the following inventions: GAS EXHAUSTER GOVERNOR - CUFF HOLDER - SEWER TRAP - DRAG SAW & Much More. These illustrations also have text that goes along with them. Very interesting advertisements as well, back in the day when many of the normal things we use today were just being invented. The 1870's was considered the heyday for new inventions which included the electric light bulb, the phonograph, the telephone & etc.