This is further expressed in the design of this monster, which has a Newton's cradle attached to its left arm. The device is named after Newton as it demonstrates his second law, the conservation of momentum and energy, via a series of swinging spheres. Additionally, mounted into the torso of this monster is a Newtonian telescope, a type of reflecting telescope. In particular, Newton constructed the world's first functional reflecting telescope, known as Newton's reflector, which would become the prototype of the Newtonian telescope. The arcs of metal seen in the spaces between the red segments of this monster may be a reference to sextants and octants, reflecting instruments used primarily in navigation. While the invention of these instruments is commonly attributed to John Hadley and Thomas Godfrey, detailed descriptions of their principles were also found in Newton's unpublished writings.