<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                   
<PERIOD-TYPE>                         YEAR
<FISCAL-YEAR-END>                     DEC-31-1997
<PERIOD-START>                        JAN-01-1997
<PERIOD-END>                          DEC-31-1997
<CASH>                                      6,337
<SECURITIES>                              149,616
<RECEIVABLES>                              45,882
<ALLOWANCES>                                1,259
<INVENTORY>                                14,537
<CURRENT-ASSETS>                           79,331
<PP&E>                                    242,911
<DEPRECIATION>                            100,455
<TOTAL-ASSETS>                            438,753
<CURRENT-LIABILITIES>                      42,995
<BONDS>                                    55,615
<PREFERRED-MANDATORY>                           0
<PREFERRED>                                     0
<COMMON>                                   10,669
<OTHER-SE>                                256,182
<TOTAL-LIABILITY-AND-EQUITY>              438,753
<SALES>                                   256,179
<TOTAL-REVENUES>                          260,034
<CGS>                                     162,715
<TOTAL-COSTS>                             162,715
<OTHER-EXPENSES>                           52,997
<LOSS-PROVISION>                            1,043
<INTEREST-EXPENSE>                          5,467
<INCOME-PRETAX>                            37,812
<INCOME-TAX>                               13,083
<INCOME-CONTINUING>                        24,729
<DISCONTINUED>                                  0
<EXTRAORDINARY>                                 0
<CHANGES>                                       0
<NET-INCOME>                               24,729
<EPS-PRIMARY>                                2.90<F1>
<EPS-DILUTED>                                2.88<F1>
<FN>
<F1>Per share amounts are adjusted to reflect 2-for-1 stock split effective March
6, 1998.
</FN>