LAWRENCE, Mass. —(?) —A former Lawrence postal em ploye was booked early Tuesday on a charge of attempting to murder his four children with iluminating gas. Deputy Police Chief Arthur J. Riley said James M. Ryley, 36, was taken to Danvers state hos pital for mental observation aft er being booked. Th 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 called police. None of the children was over come. The other children were Marilyn, 10, Eleanor, seven, and Lawrence, six. They were Ryley’s children by a previous marriage. His pres ent wife, Dorothy, a registered nurse was put on a case. The deputy police chief said that Ryley could give no explan ation for his act.