This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
John Herschel portrait. en Sir John Frederick William Herschel st Baronet KH FRS March May was an English mathematician astronomer chemist and experimental photographer who in some years also did valuable botanical work He was the son of astronomer Sir William Herschel and the father of children cs Sir John Frederick William