Chicago : Engineering and Contracting Pub. Co. · leaf 948
A ball and ^sasocket foot block is afeature of the Terry & TenchDerrick. It swings just as easilytherefore when the mast is out ofplumb asit does when the mastis vertical. There is no pintobindand eat up pow-I er if you dont plumbyour derrick--with anengineers transit.And the otherirons are…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
