ABSTRACT
DuringtheMiddleAgesoakwasalmost universallythekindofwoodemployedfor structuralpurposes,whetherforthe%"thick splitlathstripsthatsupportedtheleadroof covering,orforthehugetie-beamssetacross fromoneclerestorywall-toptotheother. VIOLLET-LE-Ducstatesspecificallythatthe woodtimberinginReimsCathedralisoak36 •
Itshouldperhapsbenotedthatinmedieval practice,becauseofhandadzinginsteadof powersawing,longstructuraltimberssuchas raftersfollowedthenaturaltaperofthetree. ThusMolesgivesthesizeoftheraftersof Lemoyne'sroofatReimsastaperingfrom 0.22msquare(8%")to0.18m(7'AI")ina lengthof17.30m(about57feet)6' .Inhis exhaustiveandinvaluabledocumentaryhistory,
SALZ~I.~Xgivesmanyinstancesofthistapering ofwoodmembers36•Hencethescantlingsi;r.es usedinthecomputationsherewithappearto bereasonableaverages.Sincethelathstrips werealwaysspacedaboutaninchapart,this itemisfiguredat4/ 5oftheareaofthetwo roofslopes.
