Philipp Deidesheimer invented the square-set system of timbering, which proved to be a magnificent milestone in mining history!
The Ophir ore body—the richest silver mine on the Comstock Lode—which had only been 10 feet wide on the 50-foot level in April of 1860, increased dramatically in size. By October, it was ranging from 40 to 50 feet in width on the 180-foot level. It was so soft and unstable an ore body that no known method of timbering would permit its extraction, and pillars of ore were totally out of the question. What was needed was support of extraordinary strength and rigidity, fashioned of readily available materials and capable of extension in any combination of directions as the ore body was stoped out. The Ophir sent to California for Philipp Deidesheimer, a distinguished mining consultant. He devised a square-set, or laid-over, cube whose edges consisted of 18 by 18 inch timbers mortised together and capable of supporting the heavy ground of the Ophir. These square-sets made mining history by allowing for the subsequent mining of heavy ore bodies wider than the maximum length of natural timbers.
In 1866, the St. Louis and Montana Mining Company asked Deidesheimer to examine a property in what is now Granite County, Montana. He gave a glowing report on the ore, and the company immediately began planning to build a mill. The James Stuart Mill, financed by James Stuart and his associates in the directorate of the St. Louis and Montana Mining Company, was built in 1867 under Deidesheimer’s supervision. The mill that Deidesheimer built, with the assistance of metallurgist Augustus Steitz and builder Horace Countryman, was the first silver amalgamation mill built in Montana and was based on the design of mills in the Comstock district known to Deidesheimer from his work there. It successfully operated using his basic design for nearly four decades, processing ore from the long-lived Hope Mine and other mines in the district.
The mining camp that was built up around the mill became known as Philipsburg in his honor. From the beginning, the residents joked that Deidesheimerburg would have been just too much of a mouthful! A letter written by a woman who lived in the camp that first year of its existence, Kate Perry, indicates that Deidesheimer also laid out the town, so its name is doubly appropriate. Philipsburg is now the county seat of Granite County.
After the decline of the Comstock mines in the late 1870s, Deidesheimer continued his successful mining career at the Young America Mine in Sierra City, California, where he was one of the five mine owners made rich over the five years of good production at that mine. However, Deidesheimer was heavily invested in San Francisco real estate at the time of the 1906 earthquake, and his fortune was largely destroyed. If Philipp Deidesheimer had patented his design for the square-set he would have made millions in royalties, but he apparently regarded his invention as a service to the safety of miners and never sought to profit from it, saying, “If all goes well and these square-sets protect the lives of the miners, what more could a man ask for?”