 Especially important was English equipment to drain mine tunnels flooded by groundwater since the Spanish period.The majority of immigrant miners came from the Cornish Central Mining District of Camborne-Redruth-Gwennap in Cornwall.The Cornish firm that ran the Real del Monte-Pachuca mines between 1824 and 1848, employed 350 Cornish miners and, when the mines were in full operation, the municipality was once the richest in the state.