Why did William Thomson become wealthy after the transatlantic cable was completed?

William Thomson, later known as Baron Kelvin, achieved significant wealth following the successful completion of the transatlantic telegraph cable by becoming a partner in two engineering consulting firms.1

These firms played a central role in the planning and construction of submarine cables during a period of rapid global expansion in communication networks. His financial success was further bolstered by his scientific contributions to the industry, specifically his patents for the mirror galvanometer and the siphon recorder, which became standard equipment on the worldwide network of submarine cables. Additionally, Thomson established a company to manufacture various electrical measuring devices and navigational instruments, such as an improved compass and tide-measuring equipment, which contributed to his status as a wealthy man who could afford a baronial estate and a private yacht.12