None.
This chalk, along with nine others, exhibited at the Deerfield Academy's new dormatory in 1932 during the "graduation season." It was so well received that headmaster Boyden asked for it to be extended to the Fourth of July holiday. There is a newspaper clipping on the exhibit, however, none of the chalks are named.
For a number of years now, we have had an old black and white image of this drawing. Found in RSW's records, it was unusual for him to have and records of his chalks. As you can see below, a side-by-side comparison lines up extrememly well. Thank you to its current owner for providing us this picture!
See also: The New Silo , an oil painting from which this chalk drawing was made.
See also: The Unfinished Silo . The silo from a different vantage point.
For more on the Silo Paintings from Dr. Mark please: Click Here