[In a Letter to the Editor] An Account of a Steam-Engine Indicator; & A Translation of Rey's Essays on the Calcification of Metals, &c. Essay XVIII; in The Quarterly Journal of Science, Literature, and the Arts, 25, 91-96; & 136-141

London: John Murray, 1822. Whole volume, iii, 454pp. 5 pll. 125 x 210mm. Half calf with marbled boards. Spine has gilt lettering, a bit rubbed. Library bookplate to front paste-down. Some foxing on the end papers and folding plates, otherwise a very good copy. An Indicator Diagram is a chart used to measure the thermal, or cylinder, performance or reciprocating steam and internal combustion engines and compressors. The indicator diagram is used to calculate the work done and the power produced in an engine cylinder or used in a compressor cylinder. It was developed by James Watt and his employee John Southern in the late 1790s. Watt kept his diagram a trade secret, using it to make radical improvements to steam engine performance, and it wasn't until 1822 (after Watt's death) that it was made public in Quarterly Journal of Science. (Wikipedia.com).