Chicago : Engineering and Contracting Pub. Co. · leaf 79
The average cost of all machine drilling inthe Ready I.illion mine for the vear I9M was$8.85 netshift for labor. $2.4:1 for explosivesand |4.9fl for power ami supplies; a total of $15.74, Security 1t.1i1.1inK. Chicago, III way b\ shaft sinking and driving headings,ilius multiplying the points of…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
