Henderson was a Scottish theologian and missionary who during the years 1814-15 travelled in Iceland on behalf of the British Bible Society. Later he wrote a book about his experiences. It is accompanied by a map of Iceland, engraved by Daniel and William Home Lizars under the direction of Henderson. The basis is the Knoff type, probably one of Jón Eiríksson's maps. But the scale is so small that few of the author's observations are reflected on the map. The chief innovation is that the Western Fiords have been moved south of the polar circle.