Thomas (1793) Doughty Paintings & Artwork for Sale | Thomas (1793) Doughty Art Value Price Guide

Aug. 12, 2026
Thomas Doughty (1793-1856) Hudson River Landscape with Figure 19 1/4 x 25 in. (48.2 x 63.5 cm.)
Est: $7,000 - $9,000
Thomas Doughty (1793-1856) Hudson River Landscape with Figure signed 'Doughty' (lower right) oil on board 19 1/4 x 25 in. (48.2 x 63.5 cm.)
Bonhams
Jan. 27, 2026
Thomas Doughty (1793-1856) Landscape 18 x 24 in. (45.7 x 61 cm.) (Painted in 1829.)
Est: $5,000 - $7,000
Thomas Doughty (1793-1856) Landscape signed and dated 'DOUGHTY / 1829' (lower right within the composition) oil on canvas 18 x 24 in. (45.7 x 61 cm.) Painted in 1829.
Bonhams
Jan. 27, 2026
Thomas Doughty (1793-1856) Fisherman on a River 11 3/4 x 17 in. (29.8 x 43.2 cm.)
Est: $4,000 - $6,000
Thomas Doughty (1793-1856) Fisherman on a River signed 'T. Doughty' (lower right) oil on panel 11 3/4 x 17 in. (29.8 x 43.2 cm.)
Bonhams
Jan. 27, 2026
Thomas Doughty (1793-1856) Desert Rock Lighthouse, Maine 27 1/4 x 34 1/4 in. (69.2 x 87 cm.) (Painted in 1836.)
Est: $15,000 - $25,000
Thomas Doughty (1793-1856) Desert Rock Lighthouse, Maine signed 'TDoughty' (lower right) oil on canvas 27 1/4 x 34 1/4 in. (69.2 x 87 cm.) Painted in 1836.
Bonhams
Dec. 07, 2025
SANDPAPER LANDSCAPE SIGNED DOUGHTY, PROB. THOMAS (1793 - 1856) HUDSON RIVER LANDSCAPE 8 3/4" 10 1/2"
Est: $400 - $800
SANDPAPER LANDSCAPE SIGNED DOUGHTY, PROB. THOMAS (1793 - 1856) HUDSON RIVER LANDSCAPE 8 3/4" 10 1/2"
Carlsen Gallery, Inc.
Nov. 18, 2025
THOMAS DOUGHTY (1793-1856) Ben Lomond 26 1/8 x 36 1/8 in. (66.3 x 91.8 cm.) (Painted in 1829-30.)
Est: $10,000 - $15,000
THOMAS DOUGHTY (1793-1856) Ben Lomond signed and dated 'T DOUGHTY / 1829-30' (lower right) oil on canvas 26 1/8 x 36 1/8 in. (66.3 x 91.8 cm.) Painted in 1829-30.
Bonhams
Oct. 30, 2025
THOMAS DOUGHTY, American 1793-1856, Storm King Near Westpoint, oil on canvas, 14 x 22 in. (35.6 x 55.9 cm.), Frame: 18 3/4 x 26 3/4 x 3 3/4 in. (47.6 x 67.9 x 9.5 cm.)
Est: $5,000 - $7,000
THOMAS DOUGHTY American, 1793-1856 Storm King Near Westpoint oil on canvas signed lower left "Doughty"
Shannon's
Oct. 17, 2025
Painting, Attributed to Thomas Doughty
Est: $600 - $900
Attributed to Thomas Doughty (American, 1793-1856), Cabin on the River, 1836, oil on canvas, bears signature and date lower right, canvas: 16.25"h x 26"w, overall (with frame): 24"h x 34"w. Provenance: Christiana Auction Gallery, April 2018, lot 180.
Clars Auctions
Oct. 03, 2025
THOMAS DOUGHTY, WASHINGTON, D.C., NEW YORK, PENNSYLVANIA, MASSACHUSETTS 1793-1856, HUDSON VALLEY LANDSCAPE, Oil on board laid on board, 13 1/2 x 18 in. (34.3 x 45.7 cm.), Frame: 19 x 23 1/2 in. (48.3 x 59.7 cm.)
Est: $2,000 - $3,000
THOMAS DOUGHTY WASHINGTON, D.C., NEW YORK, PENNSYLVANIA, MASSACHUSETTS, 1793-1856 HUDSON VALLEY LANDSCAPE Oil on board laid on board Lower right signed: T. Doughty; verso restoration label: HANNAH MEE HORNER / Restorer / PA / Sept. 36 / Rebacked / Cleaned & / Varnished
Potomack Company
Oct. 03, 2025
THOMAS DOUGHTY, WASHINGTON, D.C, NEW YORK, PENNSYLVANIA 1793-1856, HUDSON RIVER, Oil on canvas laid on board, 14 1/4 x 17 1/8 in. (36.2 x 43.5 cm.), Frame: 17 1/2 x 20 1/2 in. (44.5 x 52.1 cm.)
Est: $1,000 - $1,500
THOMAS DOUGHTY WASHINGTON, D.C, NEW YORK, PENNSYLVANIA, 1793-1856 HUDSON RIVER Oil on canvas laid on board Lower left signed on rock: T. Doughty
Potomack Company
Sep. 26, 2025
Thomas Doughty (American, 1793–1856), A View of Lake Saratoga
Est: £1,000 - £1,500
Thomas Doughty (American, 1793–1856) Hudson River School A View of Lake Saratoga Oil on board Inscribed in pencil verso and old handwritten label Estate sale without reserve Dimensions: (Frame) 14 in. (H) x 17 in. (W) (Board) 10 in. (H) x 12 in. (W)
Sloane Street Auctions
Jul. 25, 2025
ATTRIBUTED TO THOMAS DOUGHTY (New York/Pennsylvania/Massachusetts, 1793-1856), Mountain lake., Oil on canvas, 14" x 17". Framed 19" x 22".
Est: $3,000 - $5,000
ATTRIBUTED TO THOMAS DOUGHTY New York/Pennsylvania/Massachusetts, 1793-1856 Mountain lake. Unsigned. Possibly a study for Doughty's 1839 work "Two Men Fishing in a Mountain Lake", currently in the collection of the Museum of Fine Arts, Boston, accession number 64.596.
Eldred's
Jun. 01, 2025
Thomas Doughty (1793 - 1856) Antique American Hudson River School River Original Oil Painting
Est: $5,000 - $8,000
Antique American Hudson River school oil painting by Thomas Doughty (1793 - 1856). Oil on board. Measuring: 12.5 by 16.75 inches overall. Please see all images for condition. Size is measured and written on the back of the painting. The first size is the overall size, the second size is the image size. For detailed condition questions please email hello@curatedgallery.com. Domestic flat rate shipping with UPS or Fedex is set to $100 for this lot. Pick up at our 67 Guernsey street location is available 12-7pm for two weeks following the sale. Please call or email and let us know when you would like to pick up! Local delivery is also available around the area for large pieces or large orders. Flat rate $75 delivery to NYC and Brooklyn available as well. Thank you and good luck.
Curated Gallery Auctions
Apr. 30, 2025
Thomas Doughty (1793-1856) Desert Rock Lighthouse, Maine 27 1/4 x 34 1/4 in. (69.2 x 87 cm.) (Painted in 1836.)
Est: $30,000 - $50,000
Thomas Doughty (1793-1856) Desert Rock Lighthouse, Maine signed 'TDoughty' (lower right) oil on canvas 27 1/4 x 34 1/4 in. (69.2 x 87 cm.) Painted in 1836.
Bonhams
Apr. 06, 2025
THOMAS DOUGHTY (AMERICAN, 1793-1856).
Est: $1,000 - $1,500
'River Landscape with Figures and Sailboat'. 1836. Oil on canvas. Signed and dated lower right. Provenance: Kennedy Galleries, NY. Property of a California estate. Dimensions: 27.25" h x 34" w. Frame: 32" h x 39" w.
Clarke Auction Gallery
Apr. 04, 2025
ATTRIBUTED TO THOMAS DOUGHTY (New York/Pennsylvania/Massachusetts, 1793-1856), Mountain lake., Oil on canvas, 14" x 17". Framed 19" x 22".
Est: $3,000 - $5,000
ATTRIBUTED TO THOMAS DOUGHTY New York/Pennsylvania/Massachusetts, 1793-1856 Mountain lake. Unsigned. Possibly a study for Doughty's 1839 work "Two Men Fishing in a Mountain Lake" currently in the collection of the Museum of Fine Arts, Boston, accession number 64.596.
Eldred's
Dec. 08, 2024
Thomas Doughty (1793 - 1856) Antique American Hudson River School Signed 1827 Landscape Oil Painting
Est: $300 - $500
Antique American Hudson River School oil painting by Thomas Doughty (1793 - 1856). Oil on board. Signed. Measuring 8.5 by 9.5 inches. Please see all images for condition. Size is measured and written on the back of the painting. The first size is the overall size, the second size is the image size. For detailed condition questions please text 617-835-2496
Curated Gallery Auctions
Dec. 08, 2024
OIL / PANEL, LABELED & INSCRIBED, THOMAS DOUGHTY (1793- 1856) IN VERSO, UNSIGNED, HUDSON VALLEY LANDSCAPE PROVENANCE BOURGEAULT- HORAN 11 1/2" X 17 3/4"
Est: $2,000 - $4,000
OIL / PANEL, LABELED & INSCRIBED, THOMAS DOUGHTY (1793- 1856) IN VERSO, UNSIGNED, HUDSON VALLEY LANDSCAPE PROVENANCE BOURGEAULT- HORAN 11 1/2" X 17 3/4"
Carlsen Gallery, Inc.
Dec. 05, 2024
Thomas Doughty, oil on canvas, 19th c.
Est: $700 - $1,000
Thomas Doughty (American, 1793-1856), "Tintern Abbey", no signature observed, collection label, 27"h x 35"w (stretchers), 33"h x 41"w (frame)
Millea Bros Ltd
Oct. 15, 2024
Thomas Doughty (attrib.), oil on canvas
Est: $400 - $600
Attributed to Thomas Doughty (American,1793-1856), The White Mountains, no signature observed, artist tag on frame, 10"h x 15"w (stretchers), 14"h x 19"w (frame)
Millea Bros Ltd
Jun. 13, 2024
Thomas Doughty (1793-1856), BEN LOMOND, 1829-30
Est: $20,000 - $30,000
Thomas Doughty (1793-1856), American BEN LOMOND, 1829-30 signed and dated lower right Estimate: $20,000—30,000 CAD
Waddington's
Jun. 07, 2024
Thomas Doughty
Est: $3,000 - $5,000
American, 1793-1856 Morning Among the Hills Signed T. Doughty (lr) Oil on canvas 18 x 26 1/4 inches (45.7 x 66.7 cm) (Frame 29 1/2 x 37 1/2 inches) Glue relined; inpainting along the edges and a few careful touches scattered throughout.
DOYLE Auctioneers & Appraisers
Jun. 07, 2024
Thomas Doughty
Est: $3,000 - $5,000
American, 1793-1856 Delaware River Gap, 1836 Signed T. Doughtry and dated 1836 (lr) Oil on canvas 27 1/4 x 34 1/4 inches (69 x 87 cm) Provenance: Kennedy Galleries, New York Doyle, New York, Sep. 10, 2013, lot 34 (Frame 32 x 39 inches) Glue relined; the surface has alligatoring and craquelure; Extensive inpainting in the sky and scattered in the landscape.
DOYLE Auctioneers & Appraisers
May. 16, 2024
Thomas Doughty (attrib.), oil on canvas
Est: $1,000 - $1,500
Attributed to Thomas Doughty (American,1793-1856), The White Mountains, no signature observed, artist tag on frame, 10"h x 15"w (stretchers), 14"h x 19"w (frame)
Millea Bros Ltd
May. 02, 2024
THOMAS DOUGHTY, American 1793-1856, Landscape in the Hills, oil on canvas, 8 x 14 1/4 in. (20.3 x 36.2 cm.), Frame: 12 1/2 x 18 1/2 x 1 1/4 in. (31.8 x 47 x 3.2 cm.)
Est: $2,500 - $3,500
THOMAS DOUGHTY American, 1793-1856 Landscape in the Hills oil on canvas signed lower right "T. Doughty"
Shannon's
Apr. 10, 2024
Thomas Doughty
Est: $5,000 - $8,000
American, 1793-1856 Delaware River Gap, 1836 Signed T. Doughtry and dated 1836 (lr) Oil on canvas 27 1/4 x 34 1/4 inches Provenance: Kennedy Galleries, New York Doyle, New York, Sep. 10, 2013, lot 34 (framed 32 x 39 inches) Glue relined; the surface has alligatoring and craquelure; Extensive inpainting in the sky and scattered in the landscape.
DOYLE Auctioneers & Appraisers
Apr. 10, 2024
Thomas Doughty
Est: $5,000 - $8,000
American, 1793-1856 Morning Among the Hills Signed T. Doughty (lr) Oil on canvas 18 x 26 1/4 inches (Framed 29 1/2 x 37 1/2 inches) Glue relined; inpainting along the edges and a few careful touches scattered throughout.
DOYLE Auctioneers & Appraisers
Apr. 10, 2024
Thomas Doughty
Est: $6,000 - $9,000
American, 1793-1856 The Young Angler Signed T Doughty (lc) Oil on canvas 12 x 16 inches (Framed 14 1/2 x 18 1/2 inches) Scattered inpainting throughout with large areas of restorations in the upper corners.
DOYLE Auctioneers & Appraisers
Feb. 03, 2024
Doughty - Great Horned Owl. 2
Est: $100 - $200
This originally hand-colored lithograph is from John & Thomas Doughty's The Cabinet of Natural History and American Rural Sports. The work was published in Philadelphia by the authors between 1830 and 1834. This work featured the first series of color sporting prints published in America. (Bennett) Thomas Doughty was large responsible for the art work and was "hailed as 'the all-American Claude Lorrain.'" (Howat, The Hudson River and its Painters, p.31) The work was "an amalgam of natural history, sporting accounts, travel narratives, and practical advice for the countryman." (Reese) The Cabinet was very successful in its first eight issues and brought the art and practice of lithography to a wider audience. "1830 crucial in the history of American lithography for the lithographic print came of age, and this was largely through the work of Thomas Doughty” (Looney) This work "marks the beginning of dominance of lithography in book illustration." (Reese)
Trillium Antique Prints & Rare Books
Jan. 19, 2024
Camden, Maine
Est: $70,000 - $100,000
Property from a Private Collection, Maine Thomas Doughty 1793 - 1856 Camden, Maine signed Doughty and dated 1833 (lower left); signed T. Doughty and dated 1833 (lower right) oil on panel 19 ½ by 28 ½ in. 49.5 by 72.4 cm. Executed in 1833.
Sotheby's
Dec. 17, 2023
Thomas Doughty (1791 - 1856) Lithograph
Est: $300 - $500
"Fair Mount Water Works." originally painted by Thomas Doughty, printed and colored by I. Hill. with dedication to "the Select and Common Councils of the County of Philadelphia". Dimensions: Sight is 18 1/2" x 25 1/2", the frame 24 1/2" x 31"
Locati LLC
Nov. 15, 2023
19TH C. O/C, HUDSON RIVER LANDSCAPE, SIGNED DOUGHTY.
Est: $1,000 - $1,500
19th C. oil on canvas, Hudson River landscape, with a dramatic sky and sailboats along an embankment with figures sitting among rocks in the foreground. Signed lower right, T. Doughty, and labeled on back with illegible title, unframed, Canvas 8” x 10”.
William Smith Auctions
Oct. 28, 2023
THOMAS DOUGHTY, (American, 1791-1856), West Point, Hudson River, oil on board, 13 7/8 x 17 3/4 in., frame: 19 5/8 x 23 3/4 in.
Est: $5,000 - $8,000
THOMAS DOUGHTY (American, 1791-1856) West Point, Hudson River oil on board signed Doughty lower left; inscribed West Point Hudson River verso
Grogan & Company
Oct. 26, 2023
THOMAS DOUGHTY, American 1793-1856, Autumn Landscape, oil on canvas, 19 x 26 1/4 inches (48.3 x 66.7 cm.), Frame: 21 1/4 x 2 1/4 x 28 1/4 in. (54 x 5.7 x 71.8 cm.)
Est: $10,000 - $15,000
THOMAS DOUGHTY American, 1793-1856 Autumn Landscape oil on canvas signed and dated lower right "T Doughty 1848"
Shannon's
Jul. 08, 2023
THOMAS DOUGHTY (DC/NY/PA/MA, 1793-1856)
Est: $4,000 - $5,000
Hudson Valley Landscape with Hunter, oil on canvas, unsigned, copy of canvas stencil verso "Prepared by Edward Deschaux, New York" (used in that style 1844-1845 at his Broadway shop per Katlan). Housed in a vintage dull gold mitered frame, OS: 27" x 32", SS: 21 1/2" x 26 1/2", cleaned and relined.
Thomaston Place Auction Galleries
Jul. 08, 2023
ATTRIBUTED TO THOMAS DOUGHTY (DC/NY/PA/MA, 1793-1856)
Est: $3,500 - $4,500
Hudson Valley Scene with farmer calling in his cows, oil on canvas, unsigned modern watergilt and black enamel molded frame, OS: 29 12" x 37 1/2", SS: 23" x 31", overall craquelure, two repaired punctures.
Thomaston Place Auction Galleries
May. 03, 2023
Thomas Doughty (American, 1793-1856) Oil on Canvas
Est: $10,000 - $15,000
Oil on canvas attributed toÂ Thomas Doughty depicting a river landscape with a figure rowing a boat. It is 12.25" x 10" (20" x 18" framed). Painting is unsigned. Being that we are not experts and do not have any documentation, we are unable to guarantee the authenticity of this work. Frame shows some wear consistent with age. w001293701 Have a similar item to sell? Contact us at info@marketauctionsinc.com Please review all photos closely. The non-appearance of a condition report does not mean that the lot is in perfect condition, does not show wear due to age and use, or is free from damage. Market Auctions Inc. strongly suggests that you request a condition report before placing a bid. You may request one from us via this auction platform. Please note that any condition reports are given as strictly as a courtesy to interested parties and should not be considered a statement of fact. Market Auctions Inc. bears no responsibility for any error or omission. All sales are final and sold as is. Measurements are approximated. Please note shipping is not included. All collectibles, silver, antiques, and paintings please contact our third party shipper listed below: Juniors Auction Services 561-510-0345 / juniorsauctionservices@gmail.com UPS Store (561) 631-8997 / store6989@theupsstore.com DM Postal (561) 469-6137 / dmpostal5001@gmail.com For furniture and very large items, please contact an appropriate freight / transport company for shipment. SALES TAX NOTICE PLEASE TAKE NOTICE that Market Auction, Inc., only collects and remits sales tax on items purchased by Florida residents. ALL OUT OF STATE purchasers are required to pay sales tax to their respective States. Purchasers holding valid resale certificates must provide proof of same prior to purchase. Market Auctions, Inc. takes no responsibility for purchaser failure to remit sales tax to the proper non-Florida taxing authority and for any fines or penalties that may result.
Market Auctions
May. 01, 2023
Attribué à Thomas Doughty (1793-1856)
Est: CHF800 - CHF1,200
Attribué à Thomas Doughty (1793-1856) Indien dans un canoé dans un paysage, huile sur toile, 36x46 cm.
Geneve Encheres
Apr. 27, 2023
THOMAS DOUGHTY, American (1793-1856), Promenade on the Hudson, 1839, oil on canvas, 16 1/2 x 24 inches
Est: $25,000 - $35,000
THOMAS DOUGHTY American, (1793-1856) Promenade on the Hudson, 1839 oil on canvas signed and dated on the stretcher "T. Doughty 1839"
Shannon's
Dec. 08, 2022
Attribué à Thomas Doughty (1793-1856)
Est: CHF1,500 - CHF2,000
Attribué à Thomas Doughty (1793-1856) Indien dans un canoé dans un paysage, huile sur toile, 36x46 cm
Geneve Encheres
Dec. 08, 2022
Thomas Doughty (1793-1856)
Est: CHF1,500 - CHF2,000
Thomas Doughty (1793-1856) Paysage, huile sur carton, signée, 32x44 cm
Geneve Encheres
Nov. 03, 2022
Thomas Doughty American, 1793-1856 Valley of the Susquehanna
Est: $5,000 - $8,000
Thomas Doughty American, 1793-1856 Valley of the Susquehanna Oil on canvas 14 x 17 inches Provenance: Hendrickson, Doll, and Richards, Boston Maria Revere and Elizabeth "Lizzie" Rogers, Canton, MA By descent to William Bacon Revere Thence by descent to the current owners C Property from the Estate of Paul Revere Jr.
DOYLE Auctioneers & Appraisers
Nov. 03, 2022
Thomas Doughty American, 1793-1856 Autumn, circa 1835-40
Est: $5,000 - $8,000
Thomas Doughty American, 1793-1856 Autumn, circa 1835-40 Signed Doughty (ll) Oil on panel 12 7/8 x 11 3/8 inches Provenance: Private collection David David Inc., Philadelphia C Property from a Distinguished New York Collection
DOYLE Auctioneers & Appraisers
Aug. 03, 2022
Thomas Doughty (American, 1793-1856) Oil on Canvas
Est: $10,000 - $15,000
Oil on canvas attributed toÂ Thomas Doughty depicting a river landscape with a figure rowing a boat. It is 12.25" x 10" (20" x 18" framed). Painting is unsigned. Being that we are not experts and do not have any documentation, we are unable to guarantee the authenticity of this work. Frame shows some wear consistent with age. w001293701 Please review all photos closely. The nonappearance of a condition report does not mean that the lot is in perfect condition, does not show wear due to age and use, or is free from damage. Market Auctions Inc. strongly suggests that you request a condition report before placing a bid. You may request one from us via this auction platform. Please note that any condition reports are given as strictly as a courtesy to interested parties and should not be considered a statement of fact. Market Auctions Inc. bears no responsibility for any error or omission. All sales are final and sold as is. Measurements are approximated. Please note shipping is not included. All collectibles, silver, antiques, and paintings please contact our third party shipper listedÂ below: PakMail #703 (561) 491-8800 /Â pakmail703@yahoo.com UPS Store (561) 631-8997 / store6989@theupsstore.com For furniture and very large items, please contact an appropriate freight / transport company for shipment. SALES TAX NOTICE PLEASE TAKE NOTICE that Market Auction, Inc., only collects and remits sales tax on items purchased by Florida residents. ALL OUT OF STATE purchasers are required to pay sales tax to their respective States. Purchasers holding valid resale certificates must provide proof of same prior to purchase. Market Auctions, Inc. takes no responsibility for purchaser failure to remit sales tax to the proper non-Florida taxing authority and for any fines or penalties that may result.
Market Auctions
May. 26, 2022
Thomas Doughty (1793-1856) Windsor Castle 17 1/8 x 27 5/8 in. (43.5 x 70.2 cm.)
Est: $15,000 - $25,000
Thomas Doughty (1793-1856) Windsor Castle signed 'TDoughty' (lower left) oil on canvas 17 1/8 x 27 5/8 in. (43.5 x 70.2 cm.) For further information on this lot please visit the Bonhams website
Bonhams
May. 03, 2022
THOMAS DOUGHTY, AMERICAN 1793-1856, ROCKLAND LANDING, SCHUYLKILL RIVER AT FAIRMOUNT, PHILADELPHIA, 1825, Oil on panel, 5 3/8 x 8 in. (13.65 x 20.32 cm.), Frame: 9 7/8 x 12 1/4 in. (25.08 x 31.12 cm.)
Est: $4,000 - $6,000
THOMAS DOUGHTY AMERICAN, 1793-1856 ROCKLAND LANDING, SCHUYLKILL RIVER AT FAIRMOUNT, PHILADELPHIA, 1825 Oil on panel Lower left signed: T Doughty
Potomack Company
Apr. 20, 2022
AFTER THOMAS DOUGHTY (American, 1793-1856). Swans, circa 1830-33, Colored lithograph. From the Cabinet of Natural History and American
Est: $130 - $180
AFTER THOMAS DOUGHTY (American, 1793-1856). Swans, circa 1830-33, Colored lithograph. From the Cabinet of Natural History and American Rural Sports. Lithograph by Childs and Inman. Published by J. & T. Doughty, Philadelphia - Image size 6 5/8 x 8 3/8 in.; Frame: 12 x 15
Sloans & Kenyon
Mar. 21, 2022
AFTER THOMAS DOUGHTY (American, 1793-1856). Swans, circa 1830-33, Colored lithograph. From the Cabinet of Natural History and American
Est: $150 - $250
AFTER THOMAS DOUGHTY (American, 1793-1856). Swans, circa 1830-33, Colored lithograph. From the Cabinet of Natural History and American Rural Sports. Lithograph by Childs and Inman. Published by J. & T. Doughty, Philadelphia - Image size 6 5/8 x 8 3/8 in.; Frame: 12 x 15
Sloans & Kenyon