Expansion of land was difficult due to scarcity of land. Hence, land reclamation was the means they used. The earliest project of joining one landmass to another led to the emergence of seven islands of Bombay. The process began in 1784 under the governorship of William Hornby, who approved the building of a great sea wall to prevent floods. Reclamation of land from sea also continued throughout mid-nineteenth century by government and private companies. The city expanded by about 22 square miles although mounting cost forced many private companies to close down.