Moments and light fitting at Mosedale Quaker Meeting House

Mosedale Quaker Meeting House runs as a coffee shop during the summer months. I liked the impressive light fittings in this very old building. The first picture shows a light hanging on the end of a cantilevered bit of rail. It is causing an anti-clockwise moment around the first support. For equilibrium, there needs to be an equal and opposite moment. The second light could provide this but it is further from the support than the first light. Assuming that the lights have equal weight, then the clockwise moment will be bigger. But there is a second support. The reaction force at this support provides the extra anti-clockwise moment needed for equilibrium.