...; transferred from the Ministerie van Marine (Department of the Navy), The Hague, to the museum, 1883

Object number: NG-MC-76

Patent model of a simple working ladder that consists of two parts. The extending part has a small wheel at the top of each leg. Two hooks are indicated on the brace of the extending part, which when clasped on a rung of the bottom part, form the locking mechanism.

Petrus van der Loo (1806-1864) obtained a five-year patent for his improvements to ladders¹¹J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, no. 81. in 1850. His model was shown at the Exposition Universelle of 1855 in Paris.²²Expositions des produits de l’industrie de toutes les nations, 1855. Catalogue officiel, Paris (1855), p. 381.

Expositions des produits de l’industrie de toutes les nations, 1855. Catalogue officiel, Paris [1855], p. 381; J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, nos. 76-81; G. Doorman, Het Nederlandsch octrooiwezen en de techniek der 19de eeuw, The Hague 1947, no. 1845, p. 305; A.A. Lemmers, Techniek op schaal. Modellen en het technologiebeleid van de Marine 1725-1885, Amsterdam 1996, pp. 260, 355

J. van der Vliet, 2016, 'Petrus van der Loo, Model of a Ladder, The Hague, c. 1850', in J. van der Vliet and A. Lemmers (eds.), Navy Models in the Rijksmuseum, online coll. cat. Amsterdam: https://data.rijksmuseum.nl/20053225