In his article The development of the capital ship (p. 129 and further) predicted Maurice Prendergast the future demands for battleships. What he could not foresee was the arms race, the First World War followed by the Treaties for the Limitations of Naval Armaments in the 1920s and 1930 limiting the number of capital ships and their maximum displacement (35,000 tons) and calibre (40.6cm/16”).
Prediction 1910. Normal displacement 20,800 tons. Dimensions 512 x 85.5 x 28 feet. Horsepower with steam propulsion 27,000 (normal)-35,000 (extreme) ihp. Speed with steam propulsion 21 knots. Armament 10-13.5” B 45 cal guns.
British Orion-class laid down in 1909-1910, displacement 22,274 tons, dimensions 581 x 88.6 x 27.6 feet, horsepower 27,000 shp, speed 21 knots, armament 10-34.3cm/13.5 guns.
American Wyoming-class laid down in 1910, displacement 26,000 (normal)-27,680 (full load) tons, dimensions 554-562 x 93.3 x 28.6-29.7 feet, horsepower 28,000 ship, 20.5 knots speed, armament 12x12-30.5cm/12” guns.
German Kaiser-class laid down 1909-1910, displacement 24,724 (normal)-27,000 (full load) tons, dimensions 565.7 x 95.2 x 29.10 feet, horsepower 27,627 shp, 21 knots speed, armament 10-30.5cm/12” guns.
French Courbet-class laid down in 1910-1911, displacement 23,745 (normal)-25,579 (full load) tons, dimensions 544.7 x 88.7 x 29.8 feet, horsepower 28,000 hp, 21 knots speed, armament 6x2-30.5cm/12” guns.
Italian Conte di Cavour-class laid down in 1910, displacement 23,458 (standard)-25,489 (deep load) tons, dimensions 577.5 x 91.10 x 30.6 feet, horsepower 30,700-32,800 shp, 21.5 knots speed, armament 3x3&2x2-30.5cm/12” guns.
Source
Alan H. Burgoyne. The Navy League Annual 1908-1909.