whats this tool

[DAPPH]

You shouldn't need a spanner to turn it if you use it correctly. Tap, turn, tapity tap, turn. It works exactly like the old miners drills used for drilling charge holes for the dynamite. The front edge crushes the brick or rock, and turning keeps the crushed material loose.

If you wallop it in so far /hard in one or two blows & you can't rotate it by hand then putting a spanner on it and trying to turn the jumper tool will like as not see you shatter/ shear the jumper bit . There's an art to loosening the stuck tool and using a spanner isn't one . Try two hammers , one held securely against the side of the tool the other directly opposite it ,

on this side give it a few light sharp taps to the side of the tool .​

Then try rotating it by hand or pulling it out . Use a length of 1/4 " gas pipe or a thin plastic tube to blow the hole clean , Close you eyes whilst doing it then hold your breath when you've blown and let th dust settle a while afore you open them & breath in again ..it can get very dusty .​

 

[DAPPH]

the old man worked in the brickyard at Crossley's. the hard blue bits in brick were due to being incorrectly fired

Old fashioned hand made bricks made onsite from a clay pit dug in the garden often resulted in blue bricks . The suphur in the clay as well as too much heat too high for too long also had an effect in turning the center or the ends of the bricks blue . So the position of the bricks placed in the kiln was important .
Lots of the 1700's houses in the countryside had these extra strong vitrified bricks in the whole length of the chimney for they were unlikely to burn away like a normal brick would . They were a lot heavier than the normal hand made brick too.

 

[TechnicAl]

What a nightmare for lecys tv installers etc

the wires were in conduits inside the plaster...when we rewired we had to go for the "easy" route