It is impossible therefore to deduce the height of the door - frame correctly .
It is obvious from the length of the lintel and the sill that the height of this door - frame could not have been less than 15 ' .
It is impossible therefore to deduce the height of the door - frame correctly , but it is obvious from the length of the lintel and the sill that the height of this door - frame could not have been less than 15 ' .