Wikipedia :
"William Sandeman (born Luncarty, Scotland 1722, died Perth, Scotland 1790) was a leading Perthshire linen and later cotton manufacturer. For instance in 1782 alone, Perthshire produced 1.7 million yards of linen worth £81,000. Linen manufacture became by the 1760s a major Scottish industry, second only to agriculture.[1]
William was born in 1722 in Luncarty just north of Perth, Scotland the fifth child of David Sandeman and his second wife Margaret Ramsay. William with his first wife Christina Fleming had two children. With his second wife Mary Anderson he had a further 14 children (five of whom married five of the 20 children of Hector Turnbull, his bleachfield's business partner). In 1740, Robert and William Sandeman started a weaving business together, though Robert's expanding church duties in Dundee and Edinburgh removed him from the family business.[2] William was exposed to the Glasite faith after the Perth meeting house first opened in 1733.[3] He was later elected an elder of the Perth congregation for several years. In this position, he was expected to lead the congregation in both the worship and community service. As part of his Glasite obligations, he journeyed with his brother Robert in the first attempt to form a London Sandemanian congregation in 1761. When Robert extracted himself from the family business, William found another willing partner in Hector Turnbull. He was buried in the Greyfriars graveyard Perth with the inscription "William Sandeman manufacturer Perth and bleacher at Luncarty
He manufactured linen in Perth and nearby Luncarty, for instance with an order of 12,000 to 15,000 yards of "Soldiers' shirting". In 1752 he leveled 12 acres (49,000 m2) of bleachfields in Luncarty. By 1790 when William died, the Luncarty bleachfields covered 80 acres (320,000 m2) and processed 500,000 yards of cloth annually.
Linen spinning in the north of Scotland
In the early 1760s, William Sandeman opened two further linen centres: Milntown (now Milton) Easter Ross and Fortrose on the Black Isle near Inverness. By 1765, these had almost 1000 spinners.
Cotton spinning
By the 1780s, cotton was replacing linen. In November 1784, Sandeman visited Lancashire cotton mills and Richard Arkwright the inventor who had pioneered cotton-spinning machinery in Derbyshire. Sandeman, Arkwright and others established the Tay River–powered cotton mill in Stanley (just north of Luncarty, Perthshire) in 1786/7 with 3200 spindles.".
William & his second wife, Mary Anderson, had 9 sons & 5 daughters:-
1. John Sandeman 1751 - 1755
2. Sibella Sandeman 1753 - 1804 marr Robert Boswell, Writer to The Signet (Clerk to the Lord Lyon)
3. Alexander Sandeman 1755 - 1758
4. Robert Sandeman 1756 - 1772
5. Catherine Sandeman 1758 - 1806 marr Patrick Thomson
6. William Sandeman 1759 - 1761
7. Ann Sandeman 1761 - 1764
8. Thomas Sandeman 1763 - 1763
9. John Sandeman 1764 - 1792 marr Agnes Turnbull
10. Alexander Sandeman 1766 - 1766
11. William Sandeman 1766 - 1834
12. Mary Sandeman 1768 - 1844
13. Anne Sandeman 1770 - 1771
14. Jane Sandeman 1770 - 1826
Dundee University holds the records of the Glasite Church and among the manuscripts:-
"Bundle 14, No 12. To Wm Sandeman, Merchant in Perth, Scotland from John Barnard, Ironmonger Row, London, August 31st 1765. News of London. Request for help in placing a minister in Scotland."