<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET AT DECEMBER 31, 1997 AND THE CONSOLIDATED STATEMENT
OF INCOME FOR THE SIX MONTHS ENDED DECEMBER 31, 1997 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          JUN-30-1998
<PERIOD-START>                             JUL-01-1997
<PERIOD-END>                               DEC-31-1997
<CASH>                                       2,129,615
<SECURITIES>                                38,980,427
<RECEIVABLES>                                1,870,387
<ALLOWANCES>                                   158,769
<INVENTORY>                                    417,989
<CURRENT-ASSETS>                            33,316,177
<PP&E>                                      32,474,559
<DEPRECIATION>                              22,762,126
<TOTAL-ASSETS>                              83,174,637
<CURRENT-LIABILITIES>                        4,623,487
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                     4,138,462
<OTHER-SE>                                  66,792,688
<TOTAL-LIABILITY-AND-EQUITY>                83,174,637
<SALES>                                     11,066,547
<TOTAL-REVENUES>                            13,359,721
<CGS>                                        7,664,550
<TOTAL-COSTS>                               12,552,198
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                              5,821,635
<INCOME-TAX>                                 2,205,000
<INCOME-CONTINUING>                          3,616,635
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 3,616,635
<EPS-PRIMARY>                                     3.15
<EPS-DILUTED>                                     3.12