LAWRENCE, Mass., April 25. (P\—A former Lawrence postal employe was booked today on a charge of attempting to murder his four children with illuminatin gas. Deputy Police Chief Arthur J. Riley said James M. Ryley, 36 was taken to Danvers State hos pital for mental observation after being booked. The deputy said Ryley tied the four children, ranging from six to 14 years of age to chairs and then turned on gas in a kitchen stove and a jet on a gas heater. The eldest child, James, 14, freed himself, the deputy added, and notified neighbors. They call ed police. None of the children was over come. New York City’s first water mains were hollow logs.