Cooling gelatin without a refrigerator I have a pint of fruit juice, and some Gelatin. I want to make a fruit jelly (gelatin dessert) for after dinner, which will be in 8 hours. 

Living in the city with a vegetable shop around the corner, I do not have a refrigerator. It is however cold and rainy, and from experience, 6-7 hours on the windowsill will cause it to gel almost perfectly.

Are there any additional, simple tricks I can use to lower the temperature in the bowl by a few degrees more? I will be using a relatively flat bowl.
I'd place a tray in my sink a slowly run water through it, then sit the jelly on top of the tray, such that the bottom half of the jelly mould is under water. The constant, gentle, flow of cold water will cool the jelly quickly.