A city dwelling tourist visits a farm. Watching the farmer working with his cows. and never having been near one he is very impressed with the size of the beasts and the ease with which the farmer handles them. "I say farmer, these animals are huge. How much do they weigh?" Farmer gets down on his knees and has a good suck on the udder. "This one weighs in between 435 and 438 kgs." Tourist doesn't believe he can weigh a cow in that manner and demands proof. Farmer shouts his son and tells him to weigh the cow. Same story. Same weight but our tourist is not convinced which pees the farmer of a bit. "Look here you, if I get my wife down here to do it will you believe it then?" City boy agrees. Farmer sends son to the house to fetch mother but comes back alone. "Where's yer ma" screams the farmer. "She'll be here in a minuet" says son " she's just got to finish weighing the postman"