Things like this make me love my job. I challenged students to make a device to measure mass, time, temperature, or force. Two of the groups are measuring time with a water clock. One of those two groups has constucted an elegant, constant-pressure water clock (detail above). I have been enjoying watching the students collaborate, cogitate, and calibrate! I have also been enjoying observing the intensity of the effort and the interest with which they are pursuing their goals. I am looking forward to a great year of projects this year!