Photograph of rooftop view of the Marine Exchange, showing men signaling to ship, ca.1920-1929. To the right, the rectangular, flat rooftop of the Marine Exchange can be seen. At its center, a large barred structure with a pole at its top can be seen. To the left of the rooftop, two men wearing long-sleeved shirts and slacks can be seen. The man on the left can be seen holding small flags while signaling with his arms. The man on the right holds a small telescope in his hands and looks out to sea. In the extreme background, several large ships can be seen on the water.