Folder containing black and white as well as colour photographic prints, slides and negatives. The images mainly feature equipment used in experiments on the use of Heat Recovery Units in dairies carried out by A.S. Cromarty and colleagues. The file includes a colour photographic print of the Main Building at National Institute for Research in Dairying's Shinfield research facility. Some images are annotated. They have been packaged in bundles reflecting how they were organised by Cromarty.