<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE 1997
ANNUAL REPORT FOR THE YEAR ENDED APRIL 30, 1997 AND IS QUALIFIED IN ITS ENTIRETY
BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          APR-30-1997
<PERIOD-START>                             MAY-01-1996
<PERIOD-END>                               APR-30-1997
<CASH>                                          14,575
<SECURITIES>                                    19,100
<RECEIVABLES>                                   18,078
<ALLOWANCES>                                       249
<INVENTORY>                                     11,798
<CURRENT-ASSETS>                                67,718
<PP&E>                                          70,945
<DEPRECIATION>                                  42,141
<TOTAL-ASSETS>                                 105,580
<CURRENT-LIABILITIES>                           14,386
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        11,623
<OTHER-SE>                                      75,666
<TOTAL-LIABILITY-AND-EQUITY>                   105,580
<SALES>                                        121,480
<TOTAL-REVENUES>                               121,480
<CGS>                                           62,342
<TOTAL-COSTS>                                   62,342
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                 19,080
<INCOME-TAX>                                     6,585
<INCOME-CONTINUING>                                  0
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    12,495
<EPS-PRIMARY>                                     1.10
<EPS-DILUTED>                                     1.10