You pumped eight gallons of water into the tank

The summer home of Thomas Alva Edison,famous inventor,was filled with labor saving devices which he had concieved and perfected.One day, when he was showing a party of friends through the place,a guest commented that everything seemed to work smoothly except for a revolving gate in the garden.
"I had to lean all my weight against it to get past," she complained.
"Ah! when you pushed through that revolving gate,you pumped eight gallons of water into the tank on my roof,"said Edison with a twinkle in his eye!

Economist

Economist is a person who knows more about money than the people who have it!

picture courtesy: the economist magazine

What do you two talk about?

Prof.Albert Einstein,the great scientist was very unassuming and homely.A 12 year old girl used to drop in on Mr.Einstein on her way home from the school.Her parents were happy but somewhat surprised too.One evening the little girl's mother asked the professor,"What do you teo talk about everyday?"
"Oh", laughed the world famous scientist,"She brings me cookies and i do arithematic for her".