Description:
Telegraph repeater mounted on a rectangular wooden base, the wooden base sitting on an additional black metal base. There are two binding posts at the back of the base. In front of the posts are two metal cylinders (an electromagnet) connected in the back by a metal bar. A metal rod extends up from between the two cylinders and curves over and down, forming a u-shape. There are adjustment knobs on either side of the u-shape. A thin piece of metal, which is narrow at the top and wide at the bottom, extends from the center of the u-shape down to the front of the magnet. A spring extends from the thin piece of metal to a rod on top of a binding post at the front of the base. There is another binding post beside it and one behind it.
A blue triangle is painted on the corner of the wooden base and a "10" is carved on the metal base. The triangle means it was used in the department of physics at Harvard for didactic purposes.