A scratch is made at least at {TAIL ~ one corner portion} of {HEAD ~ the cathode ray tube} and heat is applied so as to flank the scratch from the two sides 
A scratch is made at least at { TAIL ~ one corner portion } of { HEAD ~ the cathode ray tube } and heat is applied so as to flank the scratch from the two sides
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH