The preparations of the prophets of Ba’al for the sacrifice are described briefly, while the description of their attempt to bring down the fire is lengthy. In contrast, Eliyahu’s preparations are described in great detail, while the description of his attempt to bring down the fire is brief. It would be a severe psychological mistake to allow the miraculous descent of fire to take place immediately after the failure of the false prophets. Hence, Eliyahu prolongs his physical preparations. The lengthening of the stage of preparations also demonstrates Eliyahu complete faith that God will answer him. 

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion