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
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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 1,153 7,012 SH   SOLE NONE 0 0 7,012
Abbott Labs COM 002824100 1,855 22,176 SH   SOLE NONE 0 0 22,176
Abbvie Inc COM 00287Y109 1,170 15,450 SH   SOLE NONE 0 0 15,450
Alphabet Cl A CAP STK CL A 02079K305 2,970 2,432 SH   SOLE NONE 365 0 2,067
Alphabet Cl C CAP STK CL C 02079K107 3,165 2,596 SH   SOLE NONE 1,039 0 1,557
Altria Group Inc COM 02209S103 476 11,649 SH   SOLE NONE 0 0 11,649
Amazon.Com COM 023135106 4,446 2,561 SH   SOLE NONE 970 0 1,591
American Express COM 025816109 213 1,800 SH   SOLE NONE 0 0 1,800
American Tower Corp COM 03027X100 6,313 28,550 SH   SOLE NONE 8,552 0 19,998
American Water Works COM 030420103 3,467 27,905 SH   SOLE NONE 8,470 0 19,435
Ametek Inc COM 031100100 3,115 33,925 SH   SOLE NONE 13,045 0 20,880
Amgen Inc COM 031162100 716 3,701 SH   SOLE NONE 0 0 3,701
Apple Computer Inc COM 037833100 5,580 24,915 SH   SOLE NONE 4,238 0 20,677
At&t Corp Com New COM 00206R102 251 6,636 SH   SOLE NONE 0 0 6,636
Bank Of Amer Corp COM 060505104 27 930 SH   SOLE NONE 0 0 930
Berkshire Hathaway Class A CL A 084670108 312 1 SH   SOLE NONE 0 0 1
Berkshire Hathaway Class B New CL B NEW 084670702 1,919 9,226 SH   SOLE NONE 1,195 0 8,031
Blackrock Inc. COM 09247X101 3,463 7,771 SH   SOLE NONE 2,720 0 5,051
Booking Hldgs Inc COM 09857L108 442 225 SH   SOLE NONE 0 0 225
Bright Horizons Family COM 109194100 2,233 14,640 SH   SOLE NONE 4,900 0 9,740
Bristol Myers Squibb Co COM 110122108 212 4,183 SH   SOLE NONE 0 0 4,183
CME Group COM 12572Q105 4,643 21,968 SH   SOLE NONE 8,015 0 13,953
Chevron Texaco Corp COM 166764100 257 2,170 SH   SOLE NONE 0 0 2,170
Cisco Systems Inc COM 17275R102 714 14,449 SH   SOLE NONE 2,496 0 11,953
Coca Cola Co COM 191216100 155 2,841 SH   SOLE NONE 987 0 1,854
Comcast Corp New Cl A CL A 20030N101 406 9,006 SH   SOLE NONE 0 0 9,006
Costco COM 22160K105 213 740 SH   SOLE NONE 0 0 740
Danaher Corp COM 235851102 5,396 37,364 SH   SOLE NONE 12,038 0 25,326
Disney Walt Co Holding Co COM DISNEY 254687106 371 2,848 SH   SOLE NONE 0 0 2,848
Dover Corp COM 260003108 2,639 26,502 SH   SOLE NONE 8,510 0 17,992
Ecolab Inc. COM 278865100 4,217 21,292 SH   SOLE NONE 7,208 0 14,084
Emerson Electric Co COM 291011104 183 2,733 SH   SOLE NONE 0 0 2,733
Equinix Inc COM 29444U700 2,847 4,935 SH   SOLE NONE 1,630 0 3,305
Exxon Mobil Corp COM 30231G102 1,035 14,652 SH   SOLE NONE 1,200 0 13,452
Facebook CL A 30303M102 521 2,927 SH   SOLE NONE 304 0 2,623
Fair Isaac Corp. COM 303250104 1,835 6,045 SH   SOLE NONE 2,080 0 3,965
First Republic Bank San Franci COM 33616C100 4,310 44,571 SH   SOLE NONE 14,320 0 30,251
Fiserv Inc Wis COM 337738108 3,442 33,225 SH   SOLE NONE 11,622 0 21,603
Genuine Parts Co COM 372460105 384 3,854 SH   SOLE NONE 0 0 3,854
Heico Corp. COM 422806109 263 2,105 SH   SOLE NONE 855 0 1,250
Home Depot Inc COM 437076102 1,923 8,290 SH   SOLE NONE 0 0 8,290
Idexx Laboratories Inc COM 45168D104 3,962 14,570 SH   SOLE NONE 5,400 0 9,170
Illumina Inc COM 452327109 3,169 10,417 SH   SOLE NONE 4,170 0 6,247
Intel Corp COM 458140100 235 4,557 SH   SOLE NONE 0 0 4,557
JP Morgan Chase COM 46625H100 9,056 76,947 SH   SOLE NONE 10,554 0 66,393
Johnson & Johnson Com COM 478160104 3,082 23,823 SH   SOLE NONE 7,785 0 16,038
Markel COM 570535104 2,269 1,920 SH   SOLE NONE 571 0 1,349
Massimo Corporation COM 574795100 1,927 12,950 SH   SOLE NONE 4,500 0 8,450
Mastercard Inc. CL A 57636Q104 7,654 28,184 SH   SOLE NONE 7,840 0 20,344
Medtronic Inc SHS G5960L103 505 4,653 SH   SOLE NONE 0 0 4,653
Merck & Co Inc New Com COM 58933Y105 981 11,652 SH   SOLE NONE 0 0 11,652
Microsoft Corp Com COM 594918104 2,437 17,526 SH   SOLE NONE 3,454 0 14,072
Netflix, Inc COM 64110L106 2,442 9,125 SH   SOLE NONE 3,645 0 5,480
Nike Inc CL B 654106103 660 7,030 SH   SOLE NONE 0 0 7,030
Novartis Ag Spon Adr SPONSORED ADR 66987V109 177 2,039 SH   SOLE NONE 0 0 2,039
Pepsico Inc COM 713448108 422 3,077 SH   SOLE NONE 0 0 3,077
Pfizer Inc Com COM 717081103 593 16,499 SH   SOLE NONE 890 0 15,609
Philip Morris International COM 718172109 604 7,950 SH   SOLE NONE 0 0 7,950
Pnc Financial Services Group I COM 693475105 124 884 SH   SOLE NONE 0 0 884
Price T Rowe Group Inc. COM 74144T108 498 4,356 SH   SOLE NONE 0 0 4,356
Procter & Gamble Co COM 742718109 1,911 15,364 SH   SOLE NONE 827 0 14,537
Roper Technologies COM 776696106 5,548 15,557 SH   SOLE NONE 5,269 0 10,288
Royal Dutch Shell Class A SPONS ADR A 780259206 1,741 29,582 SH   SOLE NONE 0 0 29,582
Steris Plc SHS USD G8473T100 1,332 9,220 SH   SOLE NONE 3,145 0 6,075
Target Corp COM 87612E106 280 2,623 SH   SOLE NONE 0 0 2,623
Teladoc Health Inc. COM 87918A105 873 12,895 SH   SOLE NONE 5,850 0 7,045
Teledyne Inc COM 879360105 311 965 SH   SOLE NONE 355 0 610
Teleflex Incorporated COM 879369106 2,356 6,935 SH   SOLE NONE 2,585 0 4,350
Teradyne COM 880770102 1,711 29,546 SH   SOLE NONE 15,931 0 13,615
Trade Web Markets, Inc. CL A 892672106 620 16,776 SH   SOLE NONE 7,565 0 9,211
Tyler Technologies Inc COM 902252105 2,102 8,009 SH   SOLE NONE 2,680 0 5,329
Unilever Plc SPON ADR NEW 904767704 459 7,637 SH   SOLE NONE 0 0 7,637
United Technologies Corp COM 913017109 423 3,100 SH   SOLE NONE 0 0 3,100
V. F. Corporation COM 918204108 380 4,267 SH   SOLE NONE 0 0 4,267
Verizon Communications COM 92343V104 745 12,347 SH   SOLE NONE 0 0 12,347
Visa Inc. COM CL A 92826C839 3,440 20,000 SH   SOLE NONE 5,137 0 14,863
Wells Fargo & Co New COM 949746101 100 1,988 SH   SOLE NONE 0 0 1,988
West Pharmaceuticals Services COM 955306105 3,018 21,279 SH   SOLE NONE 6,220 0 15,059
XYLEM Inc. COM 98419M100 1,409 17,695 SH   SOLE NONE 6,370 0 11,325
Zoetis Inc. CL A 98978V103 3,193 25,630 SH   SOLE NONE 9,000 0 16,630