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:
Vertical crosstube boiler Brockhaus. Vertical crosstube boiler Dampfkesselbrockhaus UTC Dampfkesselbrockhaus Brockhaus Berlin und Wien derivative work Andy Dingley talk cropped to extract one image Dampfkesselbrockhaus PDold original upload log This image is derivative work of the following images File Dampfkesselbrockhaus