Found by Russell & Blake Violette in Vancouver, BC, near the historic North Pacific Lumber Co mill built in 1889 by James MacLaren.
Russell states – this is an arch fire brick. Tapered depth, 4 1/2 inches height and 9 inches length.
Gartcraig Fire Clay Works, By Millerston, Glasgow.
.
.
.

James Mclaren businessman; b. 19 March 1818 in Glasgow, son of David MacLaren and Elizabeth Barnet; m. 13 Jan. 1847 Ann Sully; and they had 13 children; d. 10 Feb. 1892 in Buckingham, Que.
James Maclaren came to Upper Canada in 1822 when his father gave up his hardware trade in Glasgow to settle in Richmond. The family later moved to Torbolton Township on the Ottawa River, where David MacLaren cleared a small farm and became involved in township affairs. The family moved to Wakefield, Lower Canada, in the 1840s and James entered into business late in the decade with his brother David, forming James Maclaren and Company. Borrowing money from his father, James developed a diversified business – a general store, gristmill, woollen mill, and brick-making plant – which was successful enough to allow him to repay his father’s estate. Increasingly he became involved in buying white-pine logs and timber on the Rivière Gatineau, some of which he sold to the sawmills at New Edinburgh (Ottawa).
Source