SECURITIES AND EXCHANGE COMMISSION
          Washington, D.C. 20549

               SCHEDULE 13G

     Under the Securities Exchange Act of 1934

Name of Issuer      Cognex Corp.
Title of Class of Securities  common
CUSIP Number        192422103
Date    of   Event   Which   Requires   Filing   this   Statement
12/31/99

#1    Alex.  Brown  Investment  Management,  A  Maryland  Limited
Partnership
     52-1349876
#4   Maryland
#5   264,500
#6   0
#7   896,200
#8   0
#9   896,200
#11  2.2%
#12  PN   IA

Item 1.
     (a)  Cognex Corp.
     (b)  One Vision Drive
          Natick, MA 01760
Item 2.
     (a)  Alex.  Brown  Investment  Management,  a
          Maryland  Limited  partnership,  and   a
          registered investment advisor.
     (b)  One South Street
          Baltimore, MD  21202
     (c)  The firm is organized under the laws  of
          Maryland.    The   individual    general
          partner  is  a  citizen  of  the  United
          States of America.
     (d)  Common
     (e)  192422103
Item 3.
          (a)
          (b)
          (c)
          (d)
     X    (e)
          (f)
          (g)
          (h)
Item 4.
     (a)  896,200 shares of common stock
     (b)  2.2%
     (c)
          (i)  264,500 shares
          (ii) 0 shares
          (iii)     896,200 shares
          (iv) 0 shares
Item 5.   X
Item 6.   Not Applicable
Item 7.   Not Applicable
Item 8.   Not Applicable
Item 9.   Not applicable
Item 10.
By signing below I certify that, to the best of my
knowledge  and belief, the securities referred  to
above  were  acquired in the  ordinary  course  of
business and were not acquired for the purpose  of
and  do  not  have  the  effect  of  changing   or
influencing  the  control of the  issuer  of  such
securities  and  were not acquired  in  connection
with or as a participant in any transaction having
such purpose or effect.

Signature:
After  reasonable inquiry and to the  best  of  my
knowledge  and belief, I certify that  information
set  forth in this statement is true, complete and
correct.

ALEX. BROWN INVESTMENT MANAGEMENT
A Maryland Limited Partnership



By:
     J. Dorsey Brown, III
     Chief Executive Officer

Date:  February 15, 2000