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

Object number: NG-MC-78

Only one part of this patent model has been found. It is supposed to have consisted of three parts,¹¹J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, no. 78. of which the upper two would first simultaneously be lifted by hand and then the top part extended with a spindle.

Petrus van der Loo (1806-1864) obtained a five-year patent for his improvements to ladders²²J.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.³³Expositions 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/20053227