EXHIBIT 3




                     [PACIFIC SCIENTIFIC COMPANY LETTERHEAD]




         ChaseMellon Shareholder Services, L.L.C.
         400 South Hope Street
         4th Floor
         Los Angeles, CA 90071

         Ladies and Gentlemen:

                   Reference is hereby made to the Preferred Share
         Purchase Rights Agreement (the "Rights Agreement"), by and
         between Pacific Scientific Company (the "Company") and
         ChaseMellon Shareholder Services, L.L.C. (the "Rights Agent").

                   This letter, which upon the signature of each of the
         Company and the Rights Agent will constitute an amendment to
         the Rights Agreement, will confirm that, notwithstanding
         anything to the contrary in the Rights Agreement, the Record
         Date for the determination of shareholders of the Company who
         are entitled to receive a distribution of the Rights will be
         December 29, 1997.






                   Please indicate your acceptance of the foregoing by
         signing as indicated below.

                                  Very Truly Yours,



                                  By: /s/ Lester Hill          
                                     Title:  Chairman and Chief
                                             Executive Officer




         AGREED AND ACCEPTED:

         CHASEMELLON SHAREHOLDER SERVICES
              L.L.C.




         By: /s/ Michael Dzieciolowski   
            Title:  Relationship Manager