The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3m Co COM 88579Y101 1,215 7,012 SH   SOLE NONE 0 0 7,012
Abbott Labs COM 002824100 1,865 22,176 SH   SOLE NONE 0 0 22,176
Abbvie Inc COM 00287Y109 1,124 15,450 SH   SOLE NONE 0 0 15,450
Align Technology, Inc. COM 016255101 1,282 4,685 SH   SOLE NONE 1,695 0 2,990
Alphabet Cl A CAP STK CL A 02079K305 2,670 2,466 SH   SOLE NONE 365 0 2,101
Alphabet Cl C CAP STK CL C 02079K107 2,914 2,696 SH   SOLE NONE 1,039 0 1,657
Altria Group Inc COM 02209S103 552 11,649 SH   SOLE NONE 0 0 11,649
Amazon.Com COM 023135106 4,808 2,539 SH   SOLE NONE 970 0 1,569
American Express COM 025816109 222 1,800 SH   SOLE NONE 0 0 1,800
American Tower Corp COM 03027X100 6,011 29,400 SH   SOLE NONE 8,877 0 20,523
American Water Works COM 030420103 3,486 30,055 SH   SOLE NONE 8,470 0 21,585
Ametek Inc COM 031100100 3,082 33,925 SH   SOLE NONE 13,045 0 20,880
Amgen Inc COM 031162100 682 3,701 SH   SOLE NONE 0 0 3,701
Apple Computer Inc COM 037833100 5,040 25,465 SH   SOLE NONE 4,238 0 21,227
At&t Corp Com New COM 00206R102 176 5,246 SH   SOLE NONE 0 0 5,246
Bank Of Amer Corp COM 060505104 27 930 SH   SOLE NONE 0 0 930
Berkshire Hathaway Class A CL A 084670108 318 1 SH   SOLE NONE 0 0 1
Berkshire Hathaway Class B New CL B NEW 084670702 1,992 9,344 SH   SOLE NONE 1,195 0 8,149
Blackrock Inc. COM 09247X101 3,566 7,599 SH   SOLE NONE 2,720 0 4,879
Blackstone Group LP COM UNIT LTD 09253U108 283 6,371 SH   SOLE NONE 1,449 0 4,922
Booking Hldgs Inc COM 09857L108 422 225 SH   SOLE NONE 0 0 225
Bright Horizons Family COM 109194100 2,209 14,640 SH   SOLE NONE 4,900 0 9,740
Bristol Myers Squibb Co COM 110122108 190 4,183 SH   SOLE NONE 0 0 4,183
CME Group COM 12572Q105 4,235 21,815 SH   SOLE NONE 8,015 0 13,800
Chevron Texaco Corp COM 166764100 270 2,170 SH   SOLE NONE 0 0 2,170
Cisco Systems Inc COM 17275R102 791 14,449 SH   SOLE NONE 2,496 0 11,953
Coca Cola Co COM 191216100 163 3,210 SH   SOLE NONE 987 0 2,223
Comcast Corp New Cl A CL A 20030N101 381 9,006 SH   SOLE NONE 0 0 9,006
Danaher Corp COM 235851102 5,440 38,064 SH   SOLE NONE 12,338 0 25,726
Disney Walt Co Holding Co COM DISNEY 254687106 398 2,848 SH   SOLE NONE 0 0 2,848
Dover Corp COM 260003108 2,624 26,183 SH   SOLE NONE 8,510 0 17,673
Ecolab Inc. COM 278865100 4,391 22,241 SH   SOLE NONE 7,208 0 15,033
Emerson Electric Co COM 291011104 226 3,380 SH   SOLE NONE 0 0 3,380
Equinix Inc COM 29444U700 2,489 4,935 SH   SOLE NONE 1,630 0 3,305
Exxon Mobil Corp COM 30231G102 1,144 14,928 SH   SOLE NONE 1,200 0 13,728
Facebook CL A 30303M102 565 2,927 SH   SOLE NONE 304 0 2,623
Fair Isaac Corp. COM 303250104 1,672 5,325 SH   SOLE NONE 1,770 0 3,555
First Republic Bank San Franci COM 33616C100 4,342 44,465 SH   SOLE NONE 14,320 0 30,145
Fiserv Inc Wis COM 337738108 3,020 33,131 SH   SOLE NONE 11,622 0 21,509
Genuine Parts Co COM 372460105 399 3,854 SH   SOLE NONE 0 0 3,854
Home Depot Inc COM 437076102 1,724 8,290 SH   SOLE NONE 0 0 8,290
Idexx Laboratories Inc COM 45168D104 4,012 14,570 SH   SOLE NONE 5,400 0 9,170
Illumina Inc COM 452327109 3,793 10,302 SH   SOLE NONE 4,170 0 6,132
Intel Corp COM 458140100 218 4,557 SH   SOLE NONE 0 0 4,557
JP Morgan Chase COM 46625H100 8,603 76,947 SH   SOLE NONE 10,554 0 66,393
Johnson & Johnson Com COM 478160104 3,318 23,823 SH   SOLE NONE 7,785 0 16,038
Markel COM 570535104 2,067 1,897 SH   SOLE NONE 571 0 1,326
Massimo Corporation COM 574795100 1,917 12,884 SH   SOLE NONE 4,500 0 8,384
Mastercard Inc. CL A 57636Q104 7,674 29,009 SH   SOLE NONE 8,040 0 20,969
Medtronic Inc SHS G5960L103 444 4,560 SH   SOLE NONE 0 0 4,560
Merck & Co Inc New Com COM 58933Y105 977 11,652 SH   SOLE NONE 0 0 11,652
Microsoft Corp Com COM 594918104 2,281 17,029 SH   SOLE NONE 3,312 0 13,717
Netflix, Inc COM 64110L106 3,258 8,870 SH   SOLE NONE 3,420 0 5,450
Nike Inc CL B 654106103 590 7,030 SH   SOLE NONE 0 0 7,030
Novartis Ag Spon Adr SPONSORED ADR 66987V109 186 2,039 SH   SOLE NONE 0 0 2,039
Pepsico Inc COM 713448108 403 3,077 SH   SOLE NONE 0 0 3,077
Pfizer Inc Com COM 717081103 897 20,700 SH   SOLE NONE 890 0 19,810
Philip Morris International COM 718172109 692 8,813 SH   SOLE NONE 444 0 8,369
Pnc Financial Services Group I COM 693475105 121 884 SH   SOLE NONE 0 0 884
Price T Rowe Group Inc. COM 74144T108 478 4,356 SH   SOLE NONE 0 0 4,356
Procter & Gamble Co COM 742718109 1,685 15,364 SH   SOLE NONE 827 0 14,537
Roper Technologies COM 776696106 5,777 15,772 SH   SOLE NONE 5,239 0 10,533
Royal Dutch Shell Class A SPONS ADR A 780259206 1,925 29,582 SH   SOLE NONE 0 0 29,582
Steris Plc SHS USD G8473T100 1,341 9,004 SH   SOLE NONE 3,145 0 5,859
Target Corp COM 87612E106 227 2,623 SH   SOLE NONE 0 0 2,623
Teladoc Health Inc. COM 87918A105 856 12,895 SH   SOLE NONE 5,850 0 7,045
Teleflex Incorporated COM 879369106 2,321 7,010 SH   SOLE NONE 2,585 0 4,425
Teradyne COM 880770102 1,416 29,546 SH   SOLE NONE 15,931 0 13,615
Tyler Technologies Inc COM 902252105 1,648 7,630 SH   SOLE NONE 2,480 0 5,150
Unilever Plc SPON ADR NEW 904767704 473 7,637 SH   SOLE NONE 0 0 7,637
United Technologies Corp COM 913017109 404 3,100 SH   SOLE NONE 0 0 3,100
V. F. Corporation COM 918204108 376 4,307 SH   SOLE NONE 40 0 4,267
Varian Medical Systems COM 92220P105 218 1,600 SH   SOLE NONE 0 0 1,600
Verizon Communications COM 92343V104 705 12,347 SH   SOLE NONE 0 0 12,347
Visa Inc. COM CL A 92826C839 3,462 19,946 SH   SOLE NONE 5,137 0 14,809
Wells Fargo & Co New COM 949746101 94 1,988 SH   SOLE NONE 0 0 1,988
West Pharmaceuticals Services COM 955306105 2,663 21,279 SH   SOLE NONE 6,220 0 15,059
Worldpay Inc. CL A 981558109 3,032 24,741 SH   SOLE NONE 9,441 0 15,300
XYLEM Inc. COM 98419M100 1,488 17,795 SH   SOLE NONE 6,370 0 11,425
Zoetis Inc. CL A 98978V103 2,937 25,880 SH   SOLE NONE 9,000 0 16,880
ETF Ishares TR 2022 Term Corp IBONDS DEC22 ETF 46434VBA7 818 32,425 SH   SOLE NONE 0 0 32,425
ETF Ishares Tr Dec 2024 Term IBONDS DEC24 ETF 46434VBG4 866 34,000 SH   SOLE NONE 0 0 34,000
ISHARES TR DEC 2023 Term Co IBONDS DEC23 ETF 46434VAX8 1,108 43,600 SH   SOLE NONE 0 0 43,600