I have no idea. No bulb is visible. The top inside has a large round plate which could be covering the source of the light.
OK I will get someone to move it onto a table. What do they do then?
Can you tell me what type of bulb I will need.
That is the problem, because of its age there is no listing of a bulb, so its a case of getting the old one out and matching it up to its replacement. It may look like this one but there were various different ones fitted then -