The Ware for June 2015 is, in fact, an HV supply for driving an X-ray tube, and during normal operation it’s immersed in oil. I’ll give the prize to Matt Sieker, for being the first to correctly guess the ware.
Interesting that so many people found it to be “obviously” an HV supply for an X-ray tube — first time I had ever seen one! I found the construction details of the high voltage transformers to be interesting. Certainly a domain in which I have little direct design expertise.