Seed drill further refined by Jethro Tull in 1701 in the Agricultural Revolution. However, seed drills of this and successive types were both expensive and unreliable, as well as fragile. Seed drills would not come into widespread use in Europe until the mid to late 19th century, when manufacturing advances such as machine tools, die forging and metal stamping allowed large scale precision manufacturing of metal parts. Early drills were small enough to be pulled by a single horse, and many of these remained in use into the 1930s. The availability of steam, and later gasoline tractors, however, saw the development of
Anno 1701 were a target demographic for "Anno 1701". Upon release, "Anno 1701" broke sales records to become the fastest-selling German computer game ever, with more than 200,000 units sold in German-speaking countries during its debut two weeks. In response, Sunflowers forecast 500,000 sales by the end of 2006. It ultimately finished the year with sales of 320,000 copies in the German market alone, for revenues of €12.7 million. This placed it second for 2006, behind "World of Warcraft" at 345,000 units. On March 23, 2007, Sunflowers announced an add-on called "Anno 1701: The Sunken Dragon". It includes new features, new missions,