A concise glossary of terms used in Grecian, Roman, Italian, and Gothic architecture (1905)
Parker, John Henry, · J. Parker and Co., · leaf 220
for the purpose in eachJamb, and was usually kept suspended above the gateway,but was let down whenever an attack was apprehended:the principal entrances of almost all fortresses were pro-vided with several portcullises insuccession^ at some little distanceapart: the old grooves for them arefound… … Portcullis.
