This is supposedly a "message" from a physics professor. Read it and then read the rest of this post. http://www.centralchronicle.com/20061213/1312302.htm I believe that this is a hoax and something someone made up. This is because this was the same thing that Martin Gardner had asked a long time ago. In his book "Mathematical Magic Show" (Mathematical Association of America, 1989), he asked this exact question. On page 141, Question 23 asked "Give at least three ways a barometer can be used to determine the height of a tall building." In his answer, he gave 5: 1. Lower the barometer using a string from the roof and then measure the length of the string (this, btw, happens to correspond to the FIRST answer given by the "student" in that article). 2. Same as #1, but let it swing like a pendulum and measure the frequency or period. 3. Drop the barometer from the roof and measure the time taken. 4. On a sunny day, find the ratio of the height of the barometer to the height of the building 5. Find superitendent of the building, give him the barometer if he tells you the height of the building (this last answer happens to also correspond to the student's last answer. Coincidence? I don't think so.). My conclusion: whoever wrote the article made up this story and that this scenario never happened. I'm waiting for enough people to read this as witnesses before I write an e-mail to whoever runs this thing. Zz.