The collection consists of 23 linen drawings of dust collecting systems designed by the H. L. Day Company for use in various grain elevators and sawmills in Minnesota and other locations in the United States. Most of the drawings are concerned with the mechanics of the dust collecting system itself (such as ductwork), but some include sketches of building exteriors. They are arranged in chronological order.

Early drawings were signed by H. L. Day, later ones by the H. L. Day Company.

Removal of dust from mills and grain elevators is important because dust of any kind can be explosive; even small mills sometimes have explosions. The problem became more acute in the 1870s as mills and grain storage facilities became larger and as advances were made in the associated technology, such as the middlings purifier. The 1878 explosion of the Washburn "A" Mill, for example, destroyed not only the "A" Mill, but much of the surrounding milling district as well.