Historic Marker number 102 is located at 924 Southard Street between Grinnell and Margaret Streets.This house hides a secret when looking at it from the street. It looks like many of the homes and cottages with metal gable roofs you see throughout the Key West Historic District. Attached to the backside of the structure are house additions that have clues to the original building size, the growing space needs of its owners, and more importantly, the lack of fresh water sources on the island during the 1800s.Many homes started out as one and two room cottages due to a lack of building materials, shortage of skilled labor, and scarcity of dwellings for the island's burgeoning population in the latter half of the 1800s.As families grew and prospered, additional living space was needed. Small additions were added to the back side of the home as needed. Today it is common to see anywhere from two to four of these additions on the back of a house.Each of the additions has metal-clad gable roofs that seem to defy standard roofing logic. Roofs are traditionally designed to shed rain water away from the structure. The building additions’ multiple gable roofs run parallel to the main house gable roof and connect with each other at the lowest point creating roof valleys. The purpose of the roof valley was to collect rain water and guide it to gutters that funneled the fresh water into ground level cisterns. When the number of gabled additions increased, the surface of the new metal roof collected an additional amount of water for the cistern.Cisterns often were the sole source of water throughout the 1800s. In 1912, a reliable source of water from the mainland was supplied through pipes that were constructed along Henry Flagler's Over-Sea Railroad.These multiple gable roofed homes are called saw tooth homes because the profile of the roof peaks and valleys resemble the metal teeth of a hand saw blade.