[1] As a mariner, he served in the Mercantile Marine and ASC in South Africa, during which time he obtained the first film ever taken of a total eclipse of the Sun during a Royal Astronomical Society expedition to India in 1899, and took part in a mission in 1900 for Lloyd's of London to the South African Government to establish wireless telegraphic stations on the coast.

[3] As a result, from 1946 to 1968, whichever ship was attached to the Tay Division of the Royal Naval Reserve (in Dundee) was always temporarily renamed HMS Montrose after the 6th Duke.

In his political life, he was unpaid assistant private secretary to the Chancellor of the Exchequer in 1905, and Naval Aide-de-Camp to His Majesty.

In this speech he addressed the issue of the position of the relationship between Scottish home rule supporters and the Scotland's Irish community While he stated that he had "nothing but friendly feelings for the Irish", he added that when Ireland achieved Home Rule, "Scottish men and women were disenfranchised" and stated "as they did to us we should do to them and others.

"[7] As an engineer, he was the inventor of the world's first naval aircraft carrier, when in 1912, as a director of William Beardmore and Company of Dalmuir, he designed a 14,450 GRT merchant vessel intended for delivery to the Lloyd Sabaudo Line of Italy as the SS Conte Rosso.

The conversion work was completed in September 1918, and the vessel was commissioned as HMS Argus – recognised as the first ever "flat top".