Emblems of Mortality .. rough ashlars the Emblems of Mortality are human bones

"In the Interests of the Brethren" - notes:

[Page 74, lines 1 and 2] Emblems of Mortality .. rough ashlars the Emblems of Mortality are human bones (see also "The Rout of the White Hussars" Plain Tales from the Hills). In Freemasonry the emblems of mortality allude to the death of Hiram Abiff, the architect of the Temple in Jerusalem, who was slain "Three thousand years after the creation of the earth." Rough ashlars are unshaped stones, of which there were also plenty available from ruined buildings on the great battle fronts. They also feature in Freemasonry, where they are described as "immovable jewels" (i.e. they rest on the Wardens' pedestals); the Rough Ashlar, resting on the Junior Warden's pedestal, is described as a rough and unhewn stone, as taken from a quarry, for the entered apprentice to work on with the wooden mall and chisel. The Perfect Ashlar on the Senior Warden's pedestal is a stone of true die or square, fit only to be tried by the square and compass. Ashlar is the Middle English (asheler) from Old French aisselier (Latin axilla).