Chicago : Engineering and Contracting Pub. Co. · leaf 446
,414. Improvement in Wood PavementsHugo Akerhielm, Chicago, 111., inventor,patented June 4, 1878; application filed July14. 1877. Under this invention the blocks were treatedwith a solution made preferably as follows: 1V4part of protosulphate of iron or commercialcopperas and 1% part of chloride of… … 432 ENGINEERING & CONTRACTING Vol. XXXVI. No. 17. containing the requisite amount of water. Theblocks of wood to be treated were placed In atank or vat of a sufficient capacity, into whichtank the solution is poured until the blocks wereentirely covered. No. 206,812. Improvement in Pavements.…
Buildings
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