The other end of the arch block is supported on a spring in {HEAD ~ a blind hole} in {TAIL ~ the arched notch} 
in
The other end of the arch block is supported on a spring in { HEAD ~ a blind hole } in { TAIL ~ the arched notch }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL