<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> JUN-30-1997 <CASH> 4,149 <SECURITIES> 143,618 <RECEIVABLES> 42,807 <ALLOWANCES> 1,558 <INVENTORY> 14,539 <CURRENT-ASSETS> 69,521 <PP&E> 139,030 <DEPRECIATION> 96,285 <TOTAL-ASSETS> 416,087 <CURRENT-LIABILITIES> 30,787 <BONDS> 62,218 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 10,669 <OTHER-SE> 242,709 <TOTAL-LIABILITY-AND-EQUITY> 416,087 <SALES> 125,743 <TOTAL-REVENUES> 127,907 <CGS> 81,327 <TOTAL-COSTS> 81,327 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 557 <INTEREST-EXPENSE> 2,790 <INCOME-PRETAX> 16,584 <INCOME-TAX> 5,668 <INCOME-CONTINUING> 10,916 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 10,916 <EPS-PRIMARY> 2.55 <EPS-DILUTED> 0