Cataloged from 1906 to 1909 only these Mechanical Steam Engines are quite unique. This is a No. 525. Ives also made a 526 which was larger than the one pictured with two wheels and a fence around the base. Besides these Steam engines, IVES also cataloged two gas-style engines. Which looked similar to these but instead of a steam arm they had a No. 66 tank body on the base with either one (No. 500) or two (No. 501) wheels.

Number 240 motor, circa 1911-1912. This is the only example of this electric version that I've ever seen.