Chicago : Engineering and Contracting Pub. Co. · leaf 472
ter) 4.00 24.00 Sand and gravel (water) 4.50 28.50 Fine sand (water) 7.00 35.50 Blue drift (clay) 1.00 36.50 Blue sand 2.00 38.50 Blue drift 7.50 46.00 Hard clay 14.00 60.00 Blue drift 8.00 68.00 Sand and gravel (water) 6.00 74.00 Clay 2.00 76.00 Sand, gravel and drift (water). 6.50 82.50 Fine sand… … Section Through -Shaft At Top Seam. SINGLE GUIDE DOUBLE GUIO£
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-439-256.webp)
