Webster’s Revised Unabridged Dictionary · 1913
Buhrstone
Buhr′stone′ (bûr′stōn′), n. [OE. bur a whetstone for scythes.] (Min.) A cellular, flinty rock, used for mill stones. [Written also burrstone.]
Webster’s Revised Unabridged Dictionary · 1913
Buhr′stone′ (bûr′stōn′), n. [OE. bur a whetstone for scythes.] (Min.) A cellular, flinty rock, used for mill stones. [Written also burrstone.]