Of course enclosing does currently take place for special events like night markets.
Well, there was a time when the market was enclosed with a traditional white painted picket fence as our photo shows. We are told the photo was taken at the Queen St. end of the upper market sheds looking towards Victoria St.
Fast forward to today and you could imagine glass panels behind the pickets to keep out the worst of Melbourne's weather and keep in a level of comfort that today's consumers have come to expect.