Scientific American, Vol. 32, No. 25 (1875)
Scientific American, volume 32, number 25, is a weekly American periodical of 1875 that reported on engineering, inventions and science for a general readership of mechanics and inventors. Its pictures are line engravings of apparatus: a laboratory gas-heating setup on a table, a sectioned shaft with spiral-cut gearing and a large toothed wheel, a railway carriage with a bell-and-rope signal, and a belt-and-pulley power coupling, all drawn with crisp hatching a designer could borrow for technical diagrams.
