<ARTICLE> 5

<LEGEND>  THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
CONDENSED CONSOLIDATED BALANCE SHEET AS OF JUNE 30, 1998 AND CONSOLIDATED
STATEMENT OF INCOME FOR THE SIX MONTHS THEN ENDED AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                                
<PERIOD-TYPE>                      6-MOS
<FISCAL-YEAR-END>                           DEC-31-1998
<PERIOD-END>                                JUN-30-1998
<CASH>                                            5,523
<SECURITIES>                                          0
<RECEIVABLES>                                    90,397
<ALLOWANCES>                                          0
<INVENTORY>                                      46,302
<CURRENT-ASSETS>                                152,819
<PP&E>                                          544,715
<DEPRECIATION>                                  339,166
<TOTAL-ASSETS>                                  396,116
<CURRENT-LIABILITIES>                            85,979
<BONDS>                                               0
<PREFERRED-MANDATORY>                                 0
<PREFERRED>                                      19,616
<COMMON>                                         10,392
<OTHER-SE>                                      115,842
<TOTAL-LIABILITY-AND-EQUITY>                    396,116
<SALES>                                         305,897
<TOTAL-REVENUES>                                305,897
<CGS>                                           248,414
<TOTAL-COSTS>                                   280,916
<OTHER-EXPENSES>                                      0
<LOSS-PROVISION>                                      0
<INTEREST-EXPENSE>                                3,676
<INCOME-PRETAX>                                  21,397
<INCOME-TAX>                                      8,565
<INCOME-CONTINUING>                              12,832
<DISCONTINUED>                                        0
<EXTRAORDINARY>                                       0
<CHANGES>                                             0
<NET-INCOME>                                     12,832
<EPS-PRIMARY>                                      1.26
<EPS-DILUTED>                                      1.16