Hermanus Koekkoek – private collection. Title: Moored Sailing Vessels. Date: 1859. Materials: oil on canvas. Dimensions: 44 x 61 cm. Inscriptions: H.Koekkoek./1859 (lower right). Sold by Christie’s in Amsterdam, on May 6, 2009.. Source: https://upload.wikimedia.org/wikipedia/commons/7/77/Hermanus_Koekkoek_(sr.)_-_Moored_sailing_vessels_(1859).jpg. I have changed the light and contrast of the original photo.
Hermanus Koekkoek (Senior) – private collection. Title: Near Groningen: Loading the Two-Master on a Calm Day. Date: 1865. Materials: oil on canvas. Dimensions: 39 x 57.5 cm. Inscriptions: H. Koekkoek 1865 (lower right). Sold by Christie’s in Amsterdam, on November 18, 2008. Source: https://commons.wikimedia.org/wiki/File:Hermanus_Koekkoek_(sr.)_-_Near_Groningen-_loading_the_two-master_on_a_calm_day_(1865).jpg. I have changed the light, contrast and colors of the original photo.