Old Mechanical Engineering Building / Mechanical Engineering Laboratory
The modern Mechanical Engineering Laboratory began life as the Mechanical Engineering Building  in 1905 for a cost of $25,000.  Designed by S. Temple and James White,  the building served as both office space, with its 2-story front, and laboratory space, with its twin work bays. A 1906 addition added a 40 by 182 foot storage and laboratory section to the building's existing 80 by 182 feet. After the 1910 expansion  of the University Power House and its subsequent connection to the main building in 1914,  the total square footage of the building was brought to 44,500, at a total valuation of $92,000.  By 1914 the southern tip of the building had also become the home of the Ceramics Laboratory. 
As the building evolved, it became functionally split, with the northern half of the building occupied by the Power House (the taller section of the building that juts out) and the Concrete Preparation Laboratory.  By 1930 the southern tip of the building was home to the Highway Laboratory.  To facilitate easy cargo transfers to the building, the rail lines running through north engineering quad (on the east-west line running along the south border of Grainger) had a side line that ran down and connected to the Mechanical Engineering Laboratory near its north-west corner (the line ran due west almost the length of the Woodshop to allow trains to back up to connect back to the main line). 
When the new Mechanical Engineering Building was constructed in 1947,  the old building was renamed as the Mechanical Engineering Laboratory.
Through its 40 year tenure, the building was the home of many important innovations, including the groundwork for the Holland Tunnel ventilation system and the "Smokeless Furnace".  Until the early 1960's,  its main bay held a steam engine developed in 1871 by Professor S. W. Robinson and his students, which "supplied power to the first shop in which instruction in the mechanic arts was given in the United States". 
Within the first year of its existence, the University had created a machine shop "in which more or less of the [mechanical] students sought and found employment". A Professor of Mechanical Science had also been appointed, but he had declined the position after a year, and Professor S. W. Robinson, who had formerly taught at Michigan University, accepted the position and became the first mechanical engineering professor at the fledgling university. In 1870, the Board of Trustees had considered a request by the Department of Mechanical Engineering for $2,000 for "a steam engine, lathes, and other tools and materials for a machine shop". However, Professor Robinson wished to construction his own steam engine:
on consultation with Prof. Robinson I [Regent Gregory] consented that he should attempt the manufacture of his engine, rather than purchase it ready made, as he desired one of his own devising, with different sets of valve gears, which would enable him to exhibit several distinct forms of the steam engine, without adding materially to the expense. Prof. Robinson accordingly employed, to assist him, Mr. - Thomson, a skilled and liberally educated mechanic. They, with the assistance of the mechanical students, have made their own patterns, and an engine of ten-horse power is now completed. By raising the roof of the carpenter's shop and adding a second story a good shop has been secured at slight expense. 
Unfortunately this engine was lost during remodeling work.