On December 22, 1935, Dr. Thomas Jaggar, Director of the Hawaiian Volcano Observatory, knew that a lava flow was threatening the coastal city of Hilo.  The type of lava was called pahoehoe and develops a skin-like surface as its outer layer cools in the open air. This process builds a roof and walls that insulate the flow. Tthe lava pooled in the saddle between Mauna Loa and Mauna Key, Jaggar believed the only way to break the pool was by bombing it. On December 27, 1935, the U.S. Air Corps Bombing Squadron from Honolulu dropped twenty, 600-pound bombs at two points on the lava channel, spreading the lava and stopping the flow. Hilo was saved and Jaggar repeated the procedure in 1942. Finally,  Joe Henry is credited as the first forecaster. "The Father of Forecasts" was the first director of the Smithsonian Institution in Washington and organized the gathering of weather data through a network of 150 volunteers.  His weather spotters would gather readings then submit them to telegraph offices where operators transmitted their findings daily to Washington in the 1850s.  At the Smithsonian, Henry also presented the first weather map to the public, showing conditions submitted by his observers.  He championed the effort that "Science should be given away freely."  In addition to his initiation of weather forecasts, he invented the first practical electric motor and telegraph and dabbled in electricity, assisting in inventing the door bell and air conditioning.