Black and white photograph of a ladder with two adjustable legs over a measuring grid square on sand. Part of a camera ladder rig system developed by Merrill for taking overhead photographs of archaeological excavations. A cottage is visible behind…

Black and white photograph of a ladder with two adjustable legs over a measuring grid square on grass. Part of a camera ladder rig system developed by Merrill for taking overhead photographs of archaeological excavations. Flowers and trees are…

Black and white photograph of the Maya Sun Calendar Cycles, published by the Eugene Dietzen Co. of Chicago and New York.

Black and white photograph of a Tzolk'in calendar chart on paper.

Black and white photograph of a field in front of a dirt area next to a forest.

Black and white photograph of a field in front of a dirt area next to a forest.

Black and white photograph of a mastodon rib bone in dirt next to a ruler.

Black and white photograph of a man sitting next to a hole in the ground writing on a piece of paper. A mastodon rib is visible in the hole surrounded by measuring sticks.

Black and white photograph of four men and a tractor next to a creek. A field is visible behind a pile of dirt.

Black and white photograph of four men and a tractor working on an archaeological excavation site.

Black and white photograph of a man standing behind a partially constructed sewer trench.

Black and white photograph of a boy and a girl, David and Mary Burkhead, sitting on chairs on grass next to a house.

Black and white photograph of a boy and a girl, David and Mary Burkhead, sitting on chairs on grass next to a house.

Black and white photograph of a boy, David Burkhead, sitting on a chair on grass next to a house. His eyes are closed.

Black and white photograph of a girl, Mary Burkhead, sitting on a chair on grass next to a house.

Black and white photograph of a sidewalk lined with cottages.

Black and white photograph of Helen Burkhead (niece of Robert Merrill) and four children outside behind a house and next to a garage.

Black and white photograph, multiple exposures of the sun at different positions of a sunset at a beach. Two piers are visible in the distance.

Black and white photograph, multiple expostures of the sun at different positions of a sunset at a beach. Two piers are visible in the distance.

Black and white photograph of a two-story house at 1111 Jefferson Avenue SE, Grand Rapids, Michigan.

Black and white photograph, multiple exposures of the sun at different positions of a sunset at a beach. Two piers are visible in the distance.

Black and white lantern slide of a derailed train on the NY Central line near the Mohawk River, surrounded by a crowd of people. The image is dark and out of focus.

Black and white lantern slide of Robert Merrill (3rd from left) with members of his family in Macatawa, Michigan. Lena Billington Merrill stands at the far right. Other family members are not identified.

Black and white lantern slide of the Merrill family lakeside cottage in Macatawa, Michigan.