Among the proliferation of gauges on the backhead was the dial pressure gauge, invented by a German named Schinz in 1845. This gave the fireman a better idea of what was transpiring inside the boiler, on an easier-to-read dial, so he could better anticipate the needs of the engineer dealing with changing terrain and train weights. Before, the only gauge of pressure was a barometer triggered from inside the boiler—the crew had to figure out what the column of mercury indicated.