Sunday, August 19: The first gravity vehicle will launch at or about 12 noon from the corner of Broadway and Spring Street, and the last…well, that depends on how well things roll this year. Remember, this is not a race, but an artistic competition, and every Derby seems to include at least one or two pieces of “kinetic art” that require a fair bit of encouragement to make it in a more-or-less straight line to the bottom of the hill.