Mix all of the dry ingredients together thoroughly in a large bowl, then make a well in the centre and add the milk. Pour the mixture into the tins and pop them in the oven. Turn down the temperature to 160° after 15 minutes, then leave in the oven for another hour. The loaves should be a nice brown colour. Turn them out and give them a tap on the bottom - they should sound hollow. Leave on wire racks to cool.