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 Company COM 88579Y101 4,765 30,548 SH   SOLE   30,548 0 0
Abb ADR COM 000375204 297 13,157 SH   SOLE   13,157 0 0
Abbott Laboratories COM 002824100 9,508 103,988 SH   SOLE   103,988 0 0
Abbvie COM 00287Y109 7,181 73,138 SH   SOLE   73,138 0 0
Accenture Ltd. COM G1151C101 965 4,492 SH   SOLE   4,492 0 0
Adobe Inc COM 00724F101 9,117 20,943 SH   SOLE   20,943 0 0
Aflac Corp COM 001055102 5,730 159,048 SH   SOLE   159,048 0 0
Air Products & Chemicals COM 009158106 13,496 55,892 SH   SOLE   55,892 0 0
Alcon Inc COM h01301128 1,933 33,716 SH   SOLE   33,716 0 0
Align Technology Inc COM 016255101 284 1,034 SH   SOLE   1,034 0 0
Allegion Plc COM g0176j109 562 5,499 SH   SOLE   5,499 0 0
Allstate Corp COM 020002101 681 7,020 SH   SOLE   7,020 0 0
Alphabet Class A (Google CL A) COM 02079k305 3,634 2,563 SH   SOLE   2,563 0 0
Alphabet Class C (Google C) COM 02079k107 13,312 9,417 SH   SOLE   9,417 0 0
Altria Group Inc Com COM 02209S103 1,917 48,839 SH   SOLE   48,839 0 0
Amazon.Com Inc COM 023135106 34,910 12,654 SH   SOLE   12,654 0 0
American Express Co COM 025816109 1,553 16,318 SH   SOLE   16,318 0 0
American Tower Corporation COM 03027X100 27,529 106,479 SH   SOLE   106,479 0 0
Amgen Inc COM 031162100 2,523 10,699 SH   SOLE   10,699 0 0
Analog Devices Inc COM 032654105 1,761 14,361 SH   SOLE   14,361 0 0
ANSYS, Inc. COM 03662Q105 29,466 101,003 SH   SOLE   101,003 0 0
Antero Midstream Corp COM 03676b102 76 15,000 SH   SOLE   15,000 0 0
Apple Inc. COM 037833100 47,806 131,048 SH   SOLE   131,048 0 0
Applied Materials Inc COM 038222105 296 4,900 SH   SOLE   4,900 0 0
AptarGroup Inc COM 038336103 15,695 140,161 SH   SOLE   140,161 0 0
AT&T COM 00206R102 1,753 57,985 SH   SOLE   57,985 0 0
Automatic Data Processing COM 053015103 13,555 91,041 SH   SOLE   91,041 0 0
Avery Dennison Corp COM 053611109 389 3,410 SH   SOLE   3,410 0 0
Bank of New York Mellon COM 064058100 492 12,720 SH   SOLE   12,720 0 0
Baxter Intl COM 071813109 720 8,368 SH   SOLE   8,368 0 0
Becton Dickinson COM 075887109 6,195 25,893 SH   SOLE   25,893 0 0
Berkshire Hathaway Inc Cl A COM 084670108 802 3 SH   SOLE   3 0 0
Berkshire Hathaway Inc Cl B COM 084670702 11,690 65,489 SH   SOLE   65,489 0 0
Blackstone Group Inc COM 09260d107 235 4,146 SH   SOLE   4,146 0 0
Boston Scientific COM 101137107 1,063 30,280 SH   SOLE   30,280 0 0
Bristol-Myers Squibb COM 110122108 2,476 42,104 SH   SOLE   42,104 0 0
C D K Global COM 12508e101 207 4,986 SH   SOLE   4,986 0 0
Cambridge Bancorp COM 132152109 218 3,679 SH   SOLE   3,679 0 0
Charter Communications A COM 16119p108 315 618 SH   SOLE   618 0 0
Chevron Corp COM 166764100 6,054 67,847 SH   SOLE   67,847 0 0
Church & Dwight Inc. COM 171340102 689 8,909 SH   SOLE   8,909 0 0
Cisco Sys Inc COM 17275R102 3,953 84,761 SH   SOLE   84,761 0 0
Clorox Co COM 189054109 5,575 25,415 SH   SOLE   25,415 0 0
Coca Cola Co COM 191216100 3,415 76,423 SH   SOLE   76,423 0 0
Cognizant Corp COM 192446102 207 3,651 SH   SOLE   3,651 0 0
Coherent Inc COM 192479103 354 2,702 SH   SOLE   2,702 0 0
Colgate Palmolive COM 194162103 2,462 33,611 SH   SOLE   33,611 0 0
Comcast Corp CL A COM 20030N101 3,674 94,252 SH   SOLE   94,252 0 0
ConocoPhillips COM 20825C104 436 10,380 SH   SOLE   10,380 0 0
Constellation Brands COM 21036P108 329 1,883 SH   SOLE   1,883 0 0
Corning Inc COM 219350105 1,124 43,402 SH   SOLE   43,402 0 0
Costco Companies Inc COM 22160K105 1,909 6,295 SH   SOLE   6,295 0 0
Cree COM 225447101 1,095 18,498 SH   SOLE   18,498 0 0
Crispr Therapeutics Ag Com COM h17182108 757 10,300 SH   SOLE   10,300 0 0
CVS Health Corporation COM 126650100 10,074 155,060 SH   SOLE   155,060 0 0
Danaher Corp Del Com COM 235851102 8,823 49,893 SH   SOLE   49,893 0 0
Dentsply Sirona COM 24906p109 1,540 34,962 SH   SOLE   34,962 0 0
Diageo PLC ADR COM 25243Q205 1,579 11,752 SH   SOLE   11,752 0 0
Disney Walt Co. COM 254687106 2,799 25,103 SH   SOLE   25,103 0 0
Dollar Tree Stores COM 256746108 8,672 93,570 SH   SOLE   93,570 0 0
Dominion Energy Inc. COM 25746U109 3,648 44,941 SH   SOLE   44,941 0 0
Dover Corp COM 260003108 303 3,141 SH   SOLE   3,141 0 0
Dow Chem Co COM 260557103 328 8,059 SH   SOLE   8,059 0 0
Dupont De Nemours Inc COM 26614n102 423 7,963 SH   SOLE   7,963 0 0
Ecolab Inc COM 278865100 21,801 109,582 SH   SOLE   109,582 0 0
Eli Lilly & Co COM 532457108 1,597 9,726 SH   SOLE   9,726 0 0
Emerson Electric Co COM 291011104 587 9,463 SH   SOLE   9,463 0 0
Envista Holdings Corporation COM 29415f104 743 35,234 SH   SOLE   35,234 0 0
EOG Res Inc COM 26875P101 1,802 35,561 SH   SOLE   35,561 0 0
Eversource Energy COM 30040w108 501 6,017 SH   SOLE   6,017 0 0
Exxon Mobil Corp COM 30231G102 2,970 66,424 SH   SOLE   66,424 0 0
Facebook COM 30303m102 913 4,022 SH   SOLE   4,022 0 0
Fastenal Co COM 311900104 298 6,950 SH   SOLE   6,950 0 0
FedEx Corp. COM 31428X106 1,565 11,160 SH   SOLE   11,160 0 0
Fidelity Info Services COM 31620M106 1,103 8,223 SH   SOLE   8,223 0 0
First Republic Bank COM 33616C100 16,083 151,737 SH   SOLE   151,737 0 0
Fiserv COM 337738108 533 5,464 SH   SOLE   5,464 0 0
Fortive COM 34959j108 918 13,562 SH   SOLE   13,562 0 0
Freeport-McMoRan COM 35671D857 497 42,982 SH   SOLE   42,982 0 0
G A T X Corp COM 361448103 296 4,854 SH   SOLE   4,854 0 0
General Electric Co COM 369604103 177 25,983 SH   SOLE   25,983 0 0
General Mills Inc COM 370334104 10,797 175,135 SH   SOLE   175,135 0 0
Genuine Parts Co COM 372460105 701 8,066 SH   SOLE   8,066 0 0
Gilead Sciences Inc COM 375558103 2,970 38,605 SH   SOLE   38,605 0 0
GlaxoSmithKline Plc Spons ADR COM 37733W105 399 9,778 SH   SOLE   9,778 0 0
Global Pmts COM 37940X102 355 2,090 SH   SOLE   2,090 0 0
Globalstar Inc. COM 378973408 3 10,000 SH   SOLE   10,000 0 0
Golar LNG Ltd COM g9456a100 2,801 386,916 SH   SOLE   386,916 0 0
Guidewire Software Inc COM 40171v100 518 4,671 SH   SOLE   4,671 0 0
Hologic, Inc. COM 436440101 1,368 23,995 SH   SOLE   23,995 0 0
Home Depot Inc COM 437076102 5,844 23,330 SH   SOLE   23,330 0 0
Honeywell International Inc COM 438516106 956 6,614 SH   SOLE   6,614 0 0
Hubbell Inc COM 443510607 1,643 13,110 SH   SOLE   13,110 0 0
Hypertension Diagnostics Inc. COM 44914v104 4 36,000 SH   SOLE   36,000 0 0
ICU Medical, Inc COM 44930G107 829 4,500 SH   SOLE   4,500 0 0
Idexx Labs Inc COM 45168D104 8,521 25,808 SH   SOLE   25,808 0 0
Illinois Tool Works COM 452308109 2,186 12,502 SH   SOLE   12,502 0 0
Illumina COM 452327109 1,680 4,536 SH   SOLE   4,536 0 0
Ingersoll Rand Inc COM 45687v106 336 11,957 SH   SOLE   11,957 0 0
Intel Corp COM 458140100 4,993 83,454 SH   SOLE   83,454 0 0
International Business Machine COM 459200101 1,698 14,057 SH   SOLE   14,057 0 0
International Flavors & Fragra COM 459506101 3,210 26,211 SH   SOLE   26,211 0 0
Intuit COM 461202103 595 2,009 SH   SOLE   2,009 0 0
IQVIA Holdings Inc COM 46266c105 17,335 122,180 SH   SOLE   122,180 0 0
iShares Expanded Tech Sector E COM 464287549 558 2,000 SH   SOLE   2,000 0 0
iShares US Technology ETF COM 464287721 755 2,800 SH   SOLE   2,800 0 0
J.P. Morgan Chase & Co. COM 46625H100 6,181 65,710 SH   SOLE   65,710 0 0
Jacobs Engineering Group Inc COM 469814107 350 4,123 SH   SOLE   4,123 0 0
Johnson & Johnson COM 478160104 16,195 115,160 SH   SOLE   115,160 0 0
Kellogg Co COM 487836108 1,472 22,283 SH   SOLE   22,283 0 0
Keweenaw Land Association Ltd COM 493026108 753 12,310 SH   SOLE   12,310 0 0
Kimberly Clark Corp COM 494368103 1,538 10,884 SH   SOLE   10,884 0 0
Kinder Morgan COM 49456b101 1,132 74,644 SH   SOLE   74,644 0 0
L3Harris Technologies Inc COM 502431109 331 1,950 SH   SOLE   1,950 0 0
Lennar Corp. Class A COM 526057104 239 3,878 SH   SOLE   3,878 0 0
Lincoln Electric COM 533900106 3,621 42,987 SH   SOLE   42,987 0 0
Lincoln Natl Corp COM 534187109 378 10,275 SH   SOLE   10,275 0 0
Livongo Health Inc COM 539183103 752 10,000 SH   SOLE   10,000 0 0
LKQ Corp. COM 501889208 3,546 135,336 SH   SOLE   135,336 0 0
Lowe's Companies COM 548661107 4,568 33,810 SH   SOLE   33,810 0 0
Marsh & McLennan COM 571748102 33,508 312,082 SH   SOLE   312,082 0 0
Mastercard Inc. COM 57636q104 430 1,453 SH   SOLE   1,453 0 0
McCormick & Co. Inc COM 579780206 13,292 74,087 SH   SOLE   74,087 0 0
McDonald's Corp COM 580135101 6,722 36,437 SH   SOLE   36,437 0 0
Medtronic PLC COM g5960l103 768 8,371 SH   SOLE   8,371 0 0
Merck & Co COM 58933Y105 6,875 88,900 SH   SOLE   88,900 0 0
Microchip Technology Incorpora COM 595017104 457 4,344 SH   SOLE   4,344 0 0
Microsoft Corp COM 594918104 30,888 151,776 SH   SOLE   151,776 0 0
Middleby COM 596278101 4,413 55,907 SH   SOLE   55,907 0 0
Mondelez International COM 609207105 2,385 46,645 SH   SOLE   46,645 0 0
Neogen COM 640491106 5,005 64,496 SH   SOLE   64,496 0 0
Nestle SA-spons ADR COM 641069406 12,151 110,028 SH   SOLE   110,028 0 0
Newmont Corp. COM 651639106 216 3,500 SH   SOLE   3,500 0 0
NextEra Energy COM 65339F101 11,314 47,109 SH   SOLE   47,109 0 0
Nike Inc Cl B COM 654106103 17,371 177,166 SH   SOLE   177,166 0 0
Norfolk Southern COM 655844108 3,182 18,123 SH   SOLE   18,123 0 0
Northern Tr Corp COM 665859104 997 12,570 SH   SOLE   12,570 0 0
Novartis AG ADR COM 66987V109 1,601 18,325 SH   SOLE   18,325 0 0
Novo Nordisk A/S ADR COM 670100205 3,052 46,609 SH   SOLE   46,609 0 0
NVIDIA Corp COM 67066G104 284 748 SH   SOLE   748 0 0
Oracle Systems Corp COM 68389X105 1,892 34,228 SH   SOLE   34,228 0 0
Otis Worldwide COM 68902v107 304 5,351 SH   SOLE   5,351 0 0
Parker Hannifin COM 701094104 2,901 15,827 SH   SOLE   15,827 0 0
Paypal Holdings Inc COM 70450y103 1,017 5,835 SH   SOLE   5,835 0 0
PepsiCo COM 713448108 9,804 74,126 SH   SOLE   74,126 0 0
Pfizer COM 717081103 2,821 86,257 SH   SOLE   86,257 0 0
Philip Morris International COM 718172109 2,737 39,065 SH   SOLE   39,065 0 0
PNC Financial Services COM 693475105 405 3,850 SH   SOLE   3,850 0 0
Price T. Rowe Group COM 74144T108 251 2,033 SH   SOLE   2,033 0 0
Procter & Gamble COM 742718109 11,796 98,650 SH   SOLE   98,650 0 0
Qualcomm COM 747525103 1,960 21,490 SH   SOLE   21,490 0 0
Raytheon Technologies COM 75513e101 2,142 34,768 SH   SOLE   34,768 0 0
Roche Holdings LTD ADR COM 771195104 393 9,054 SH   SOLE   9,054 0 0
Rockwell Automation COM 773903109 17,222 80,853 SH   SOLE   80,853 0 0
Roper Technologies COM 776696106 13,136 33,833 SH   SOLE   33,833 0 0
Royal Dutch Shell PLC ADR A COM 780259206 348 10,647 SH   SOLE   10,647 0 0
RPM COM 749685103 4,304 57,345 SH   SOLE   57,345 0 0
S & P Global COM 78409v104 9,200 27,924 SH   SOLE   27,924 0 0
Salesforce.com Inc COM 79466l302 8,504 45,397 SH   SOLE   45,397 0 0
Schlumberger Ltd COM 806857108 276 15,026 SH   SOLE   15,026 0 0
Science Applications Internati COM 808625107 212 2,735 SH   SOLE   2,735 0 0
Seagate Technology COM g7945m107 1,113 23,000 SH   SOLE   23,000 0 0
ServiceNow Inc COM 81762p102 2,989 7,379 SH   SOLE   7,379 0 0
Sherwin Williams COM 824348106 5,058 8,754 SH   SOLE   8,754 0 0
Skyworks Solutions COM 83088M102 630 4,930 SH   SOLE   4,930 0 0
SolarEdge Technologies COM 83417m104 3,393 24,450 SH   SOLE   24,450 0 0
Southern Nat'l Bancorp of VA COM 843395104 222 22,900 SH   SOLE   22,900 0 0
SPDR S&P Biotech COM 78464A870 7,063 63,091 SH   SOLE   63,091 0 0
Splunk Inc COM 848637104 1,515 7,626 SH   SOLE   7,626 0 0
Square Inc. COM 852234103 779 7,425 SH   SOLE   7,425 0 0
SS&C Technologies Holdings COM 78467J100 2,495 44,170 SH   SOLE   44,170 0 0
Stanley Black & Decker COM 854502101 797 5,718 SH   SOLE   5,718 0 0
Starbucks COM 855244109 366 4,975 SH   SOLE   4,975 0 0
Starwood Property Trust COM 85571B105 636 42,525 SH   SOLE   42,525 0 0
Stericycle COM 858912108 3,260 58,233 SH   SOLE   58,233 0 0
Steris PLC New COM g8473t100 817 5,325 SH   SOLE   5,325 0 0
Stryker COM 863667101 10,323 57,292 SH   SOLE   57,292 0 0
Sysco COM 871829107 314 5,750 SH   SOLE   5,750 0 0
Target COM 87612E106 1,924 16,045 SH   SOLE   16,045 0 0
TE Connectivity COM H84989104 8,717 106,886 SH   SOLE   106,886 0 0
Teradyne COM 880770102 1,166 13,800 SH   SOLE   13,800 0 0
Texas Instruments Inc COM 882508104 444 3,500 SH   SOLE   3,500 0 0
The Estee Lauder Companies Inc COM 518439104 300 1,589 SH   SOLE   1,589 0 0
The Trade Desk Inc A COM 88339j105 203 500 SH   SOLE   500 0 0
Thermo Fisher Scientific COM 883556102 13,646 37,661 SH   SOLE   37,661 0 0
Thor Industries COM 885160101 3,497 32,824 SH   SOLE   32,824 0 0
TJX COM 872540109 410 8,117 SH   SOLE   8,117 0 0
Trane Technologies COM g8994e103 1,206 13,555 SH   SOLE   13,555 0 0
Travelers Companies Inc COM 89417E109 359 3,150 SH   SOLE   3,150 0 0
Tyler Technologies COM 902252105 871 2,510 SH   SOLE   2,510 0 0
UGI Corp COM 902681105 223 7,000 SH   SOLE   7,000 0 0
Unilever PLC ADR COM 904767704 364 6,630 SH   SOLE   6,630 0 0
Union Pacific Corp COM 907818108 23,298 137,798 SH   SOLE   137,798 0 0
United Parcel Service COM 911312106 574 5,160 SH   SOLE   5,160 0 0
UnitedHealth Group Inc COM 91324P102 774 2,624 SH   SOLE   2,624 0 0
Valero Energy COM 91913Y100 269 4,573 SH   SOLE   4,573 0 0
Vanguard Real Estate ETF COM 922908553 1,064 13,555 SH   SOLE   13,555 0 0
Verizon Communications COM 92343V104 8,376 151,933 SH   SOLE   151,933 0 0
Viaspace Inc. COM 92554W106 0 207,550 SH   SOLE   207,550 0 0
Visa Inc Class A COM 92826C839 22,732 117,679 SH   SOLE   117,679 0 0
W.P. Carey COM 92936u109 273 4,035 SH   SOLE   4,035 0 0
Wabtec Corp COM 929740108 307 5,338 SH   SOLE   5,338 0 0
Wal-Mart Stores Inc COM 931142103 776 6,476 SH   SOLE   6,476 0 0
Walgreen Boots Alliance COM 931427108 443 10,450 SH   SOLE   10,450 0 0
Waste Management COM 94106L109 4,104 38,748 SH   SOLE   38,748 0 0
WEC Energy Group COM 92939u106 498 5,685 SH   SOLE   5,685 0 0
Wells Fargo Company COM 949746101 211 8,256 SH   SOLE   8,256 0 0
Welltower COM 95040q104 1,401 27,066 SH   SOLE   27,066 0 0
Weyerhaeuser Co COM 962166104 1,791 79,760 SH   SOLE   79,760 0 0
Xylem COM 98419m100 3,827 58,919 SH   SOLE   58,919 0 0
Yum China Holdings COM 98850p109 316 6,584 SH   SOLE   6,584 0 0
Zebra Tech Corp Cl A COM 989207105 19,349 75,596 SH   SOLE   75,596 0 0
Invesco QQQ Trust EFT 46090E103 9,616 38,837 SH   SOLE   38,837 0 0
iShares 500 Growth Index Fund EFT 464287309 1,092 5,264 SH   SOLE   5,264 0 0
iShares Core MSCI EAFE EFT 46432f842 389 6,805 SH   SOLE   6,805 0 0
iShares Core S&P Mid-Cap EFT 464287507 1,983 11,152 SH   SOLE   11,152 0 0
iShares MSCI Emerging Markets EFT 464287234 4,189 104,752 SH   SOLE   104,752 0 0
iShares Russell 1000 Growth EFT 464287614 244 1,272 SH   SOLE   1,272 0 0
iShares Russell 2000 Growth EFT 464287648 937 4,530 SH   SOLE   4,530 0 0
iShares Russell 2000 Index Fun EFT 464287655 1,203 8,401 SH   SOLE   8,401 0 0
iShares Russell Micro-cap Inde EFT 464288869 265 3,033 SH   SOLE   3,033 0 0
iShares Russell Mid-Cap Index EFT 464287499 1,117 20,832 SH   SOLE   20,832 0 0
iShares S&P 500 Index Fund EFT 464287200 1,736 5,605 SH   SOLE   5,605 0 0
iShares S&P 500 Value Index Fu EFT 464287408 671 6,205 SH   SOLE   6,205 0 0
iShares S&P SmallCap 600 Index EFT 464287804 10,605 155,288 SH   SOLE   155,288 0 0
SPDR S&P 500 EFT 78462F103 23,590 76,503 SH   SOLE   76,503 0 0
SPDR S&P Dividend EFT 78464A763 603 6,616 SH   SOLE   6,616 0 0
SPDR S&P MidCap 400 EFT 78467Y107 12,017 37,034 SH   SOLE   37,034 0 0
VanEck Vectors Morningstar Int EFT 92189f593 730 25,848 SH   SOLE   25,848 0 0
VanEck Vectors Morningstar Wid EFT 92189f643 1,309 25,055 SH   SOLE   25,055 0 0
Vanguard Dividend Appreciation EFT 921908844 2,777 23,702 SH   SOLE   23,702 0 0
Vanguard Extended Market EFT 922908652 2,498 21,111 SH   SOLE   21,111 0 0
Vanguard FTSE All-World Ex-US EFT 922042775 2,976 62,518 SH   SOLE   62,518 0 0
Vanguard FTSE Developed Market EFT 921943858 2,785 71,797 SH   SOLE   71,797 0 0
Vanguard FTSE Emerging Mkts EFT 922042858 11,530 291,088 SH   SOLE   291,088 0 0
Vanguard High Dividend Yield EFT 921946406 381 4,830 SH   SOLE   4,830 0 0
Vanguard Large-Cap EFT 922908637 1,294 9,049 SH   SOLE   9,049 0 0
Vanguard Mid-Cap EFT 922908629 869 5,300 SH   SOLE   5,300 0 0
Vanguard S&P 500 EFT 922908363 718 2,534 SH   SOLE   2,534 0 0
Vanguard Small-Cap EFT 922908751 385 2,640 SH   SOLE   2,640 0 0
Vanguard Total Intl Stock ETF EFT 921909768 2,389 48,583 SH   SOLE   48,583 0 0
Vanguard Total Stock EFT 922908769 4,373 27,934 SH   SOLE   27,934 0 0
Wisdomtree Emerging Mkts Sm Ca EFT 97717W281 1,126 28,869 SH   SOLE   28,869 0 0
IShares UK Property UCITS ETF COM IE00B1TXL 229 37,400 SH   SOLE   37,400 0 0