The Japs gave ground on Saipan. Thunderbolts of the 318th bored in to clear the way for the final lunge, then orbitted overhead as the American flag went up on Marpi Point. On July 9, the island was declared source. A navy specialist reported in with word of a new bomb project recently completed at Eglin Field. From the materials at hand, ground crewmen built the necessary loading facilities. Ordnance made some improvements in the detonator. On the afternoon of July 23rd, men crowded on top of the old block house or perched on red earth bunkers to watch the group's P-47's bomb Tinian with wing and belly tanks which, for the first time in the war, were filled with the new mixture called Napalm. From the same vantage points they saw Marines pour ashore for the July 24-31 battle of Tinian, their assault boats guided to the landing beach by low-flying Thunderbolts of the 318th. With the fall of Tinian and the invasion of Guam, the 318th turned more and more attention to neutralization. It raced down to Rota and up to Pagan and bored through anti-aircraft barrages to plaster runways with bombs until the by-passed enemy air bases no longer were a threat. B-25's and then B-24's jammed Isley Field and the newly constructed strip first known as Isley #2 and then designated Kobler Field in memory of First Lieutenant Wayne F. Kobler, a 19th Fighter Squadron pilot kill in the early days of the Marianas campaign. War fanned out from the Marianas toward the Volcanos and Bonins to the north and the Carolines to the south. Engineers changed the face of Aslito Airfield and orders changed its name to Isley. During the last week in July (officially on July 24) the 318th moved to the muddy cane fields beside the newly completed East Field runway on Kagman Point.