Merrimac Industries 8-K Changes in Registrant.s Certifying Accountant

                                                                    Exhibit 16.1


April 26, 2007


U.S. Securities and Exchange Commission
Office of the Chief Accountant
100 F Street, NE
Washington, DC 20549


Re:    Merrimac Industries, Inc.
       File No. 0-11201


Dear Sir or Madam:


We have read Item 4.01 of Form 8-K of Merrimac Industries, Inc. dated April 26,
2007 and agree with the statements concerning our Firm contained therein.


Very truly yours,

/s/ Grant Thornton LLP