Possibly a window sill but broken i.e. only the LH part — note the sloping top and dressed front. ????

John

The far slot is for a cramp, the near one could be too, but could conceivably be a lewis hole, for lifting – the block broken in half at this point.

Half of the sill of one of the bay windows?

Yes exactly that, a staple glued in with molten lead.

A lewis is a method of lifting usually involving three keys or feathers linked by a shackle, placed in a dovetail-shaped hole – the outer two flare out at the bottom to form a dovetail shape, and are inserted first, followed by a central parallel-sided one to keep them from closing. Once all three are in they are linked by the shackle and lifted – a brilliantly simple idea going back millennia that’s never really been bettered (only made cheaper!).

The masons of old used manual winches and windlasses, blocks and tackle, levers…. and muscles.

Scaffolding was essentially long tree-trunks joined by lashings. The ancestor of the “putlog” cross-member we know as a tube with a flattened end to fit between courses, came from literally “put log” – a small stone left out of the wall to give a cavity for the timber cross-member to rest in. Some are still visible in the outer walls of Salisbury Cathedral where they evidently forgot to plug them! Can’t get the staff…

The enormous roof-trusses in such buildings were fabricated to jigs on the floor, marked up, dismantled and lifted piece-by-piece for assembly in place.

Henry VIII gave one of his wives a psaltery whose artwork includes a wonderful impression of building the Tower Of Babel. Artists of the time dressed Middle Eastern, Biblical characters in contemporary Western European clothes, and the illustration similarly shows what would have been Tudor building techniques. These include familiar marking-out and cutting tools still used by stone-masons, and a curiously double-drummed, manual winch for lifting blocks to the fixers. The latter might be an inaccurate representation of a two-fall rope and pulley – I don’t know if the differential windlass was in use that long ago.

Modern engineering technicians – the manufacturer’s fitters who assembled the giant engines as at Kew Bridge Pumping-Station – were often helped by teams of ex-seamen skilled in manipulating very heavy and awkward parts at great heights, by block and tackle, and muscle-power.

Builders today still use ropes and gin-blocks for raising small loads like fittings and buckets of mortar to the upper levels of scaffolding; but I have also seen a roofing-contractor using a portable conveyor like a straw-elevator to deliver tiles.