Galerie
Napoléon
- Paris - Collection of the Prints & Drawings

Prints & Drawings | Architecture

18039 artworks in this category
XXth Century
Mills - Pont-de-Ruan - Indre - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63436

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 13.5 x 22.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
View of Vouvray - Loire - Church - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63435

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 22.5 x 17.5 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
La Grenadière - Saint-Cyr-sur-Loire - Loire - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63434

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 14.0 x 18.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Hotel Raimbault - Rue du Mûrier - Vieux-Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63433

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 18.0 x 13.5 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Maison de la Belle Teinturière - Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63432

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 17.5 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Maison du Curé - Tours - Vieux-Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63431

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 18.0 x 17.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Cathedral of Tours - Indre et Loire (France)  | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1949

20th Century (1949)

Inventory N° : FR-63429

  • Wood engraving
  • 1949
  • XXth Century
  • Paper
  • 23.5 x 13.5 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1949]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
House of the Courteline family - Butte Montmartre - Paris (France) | Original print after Courteline. 1958

20th Century (1958)

Inventory N° : FR-63427

  • Print
  • 1958
  • XXth Century
  • Paper
  • 13.0 x 18.0 cm
  • 25.0 x 32.0 cm

20th Century [1958]

100€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Antique houses - Place du Tertre - Montmartre - Paris 18th arrondissement (France)  | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63425

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 13.5 x 18.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Moulin de la Galette - Montmartre - Paris 18th arrondissement (France)  | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958
SOLD
Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Place du Tertre - Montmartre - Paris 18th arrondissement (France)  | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63423

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 14.0 x 18.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Quai Port-Bretagne under the snow - Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63421

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 24.5 x 18.5 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Bar-le-Duc - Notre-Dame Bridge - Meuse (France)  | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63420

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 14.0 x 21.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Cathedral of Meaux - Seine-et-Marne (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63417

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 15.0 x 19.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Basilica of the Sacred Heart - Montmartre - Paris 18th arrondissement (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63416

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 20.0 x 16.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Tours - Church Notre-Dame de la Riche - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63412

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 24.0 x 17.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Old threshold - Rue Georges Courteline - Vieux-Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63410

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 18.0 x 14.5 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Birthplace of Georges Courteline - Vieux-Tours - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1958

20th Century (1958)

Inventory N° : FR-63409

  • Wood engraving
  • 1958
  • XXth Century
  • Paper
  • 18.0 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1958]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Priory of St. Cosmas - Tours - Church ruins - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63408

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 14.0 x 17.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Pont Royal - Pavillon de Flore - Louvre - Seine - Paris (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63407

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 18.0 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Church of Saint Germain l'Auxerrois - 1st arrondissement of Paris (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63406

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 17.5 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Old courtyard - Rue du Fer-à-Moulin - 5th arrondissement of Paris (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63405

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 13.5 x 17.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Old houses - Rue Lacépède - 5th district of Paris (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63404

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 14.0 x 18.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Priory of St. Cosmas - Tours - Apse chapels- Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63403

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 13.5 x 17.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Priory of St. Cosmas - Tours - Ronsard - Indre-et-Loire (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63402

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 14.0 x 18.0 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Old well - Château de Talcy - Renaissance - Loir-et-Cher (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63401

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 18.0 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Castle of la Possonnière - Couture-sur-Loir - Ronsard - Loir-et-Cher (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63400

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 14.0 x 17.5 cm
  • 25.0 x 32.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Château de Blois - Castle of Blois - Loir-et-Cher - Francis I wing (France) | Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist. 1954

20th Century (1954)

Inventory N° : FR-63399

  • Wood engraving
  • 1954
  • XXth Century
  • Paper
  • 17.5 x 14.0 cm
  • 32.0 x 25.0 cm

Original wood engraving drawn by Ferdinand Dubreuil. Signed in the margin by the artist...

20th Century [1954]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Fountain of the Odalisque - Generalife Garden - Granada (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63380

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 23.5 x 18.0 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Palau abandonat - Abandoned Palace - Granada (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63378

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 15.5 x 14.5 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Faun Garden - Basin - Majorca (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63369

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 14.5 x 18.0 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Royal Palace of La Granja - Garden - Castile and León (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63366

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 11.5 x 14.5 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Alberca - Palace of Comares - Alhambra - Granada (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63360

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 17.0 x 22.5 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
Generalife Gardens - Alhambra - Fountains - Granada (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63351

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 21.0 x 15.0 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XXth Century
La Granada church - Barcelona (Spain) | Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century (1903)

Inventory N° : FR-63350

  • Print
  • 1903
  • IIIrd Republic
  • Paper
  • 20.5 x 14.5 cm
  • 42.0 x 29.5 cm

Original print after Santiago Rusiñol. Applied on heavy paper. Dry seal. 1903

20th Century [1903]

150€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
Former chapel Moret - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63348

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 26.0 x 15.5 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
15th century house - Rue du Pont Ginguet - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63346

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 26.0 x 17.0 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
15th century house - Rue d'Allier - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63345

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 27.0 x 15.0 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
15th century house - Rue du Creux du Verre - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63344

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 25.0 x 16.0 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
Renaissance house - Rue de l'Horloge - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63343

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 26.0 x 20.0 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
Clock Tower - Tour Jacquemart - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63342

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 27.0 x 14.0 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging
XIXth Century
Renaissance house - Rue de l'Horloge - Moulins - Allier (France) | Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century (1889)

Inventory N° : FR-63341

  • Lithography
  • 1889
  • IIIrd Republic
  • Thick paper
  • 28.5 x 15.5 cm
  • 37.0 x 27.0 cm

Original auto-lithograph drawn by Le Roy de Chavigny. 1889

19th Century [1889]

160€
  • Shipment within 24H
  • Certificate of authenticity
  • Passepartout included
  • Secured packaging