Edge on Science is offering a $100 discount on remaining spaces in this week’s Catapult Engineering course for ages 10-14, August 7-11 at Gann Academy. Learn how to build a trebuchet and how to use it to knock down a castle wall. Our favorite testimonial quotes:

“My son loved every single minute. This is such a hidden gem! We’re so happy we found it & will come again!” —Cindy C., parent

“I wish we had this when I was 10!” —King Richard I of England (1157-1199)