ridge or the masonry.There are two general types of rollers,the circular rollers,and thesegmental rollers. Fig.U-2 shows a nest of circular rollers,which rest directlyupon the masonry plate. The masonry bed-plate and the shoe-plate ofthe pedestal have narrow plates attached to their bearing…
![An illustration from Vnderweysung der Messung : mit dem Zirkel vn[d] Richtscheyt in Linien, Ebnen vnnd gantzen Corporen (1525)](https://img.insideoutlibrary.com/img/200/ia-vnderweysungderm00drer-95-192.webp)
