Black and white photograph of a man working in front of a cave opening on a hillside.

Black and white lantern slide of an excavated gravesite. The label on the slide reads, "Interm. Skeleton under slabs."

Black and white photograph of the Daisy Geyser in eruption, Yellowstone National Park. A man is seen walking next to the geyser.

Black and white close-up photograph of a dam. Taken my Merrill while attending the American Society of Civil Engineers conference in New Orleans, Louisiana.

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 baby, David Burkhead, in a high chair.

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 the gravestone of Deacon John Shute (range 4 row 8) which reads, "Here Lies Buried the Body of Deacon John Shuke who departed this Life Sep 30 1780 in y 88 Year of His Age."

Black and white photograph of four people standing in front of the arch in the Wawona tree at Yosemite. A sign above the arch reads, "Dead Giant."

Black and white lantern slide of an excavated burial site. The lantern is labeled "Deep skeleton, uppermost section."

Black and white lantern slide of a "deep fireplace" at the Uyak Bay site.

Black and white photograph (slightly overexposed) of a man and a woman standing next to the Demon's Anvil stone formation at Wisconsin Dells. A lake is visible in the background.

Black and white photograph of a field in front of a hill in Otsego County, New York.

Black and white photograph of a ladder in front of a tree next to a cottage. Part of a camera ladder rig system developed by Merrill for taking overhead photographs of archaeological excavations.

Black and white photograph of 13 people standing and fishing on a wooden bridge. Rock formations and a brick wall are visible behind the bridge. "Devil's Hole, Bermuda Fine Fishing." is written on the bottom of the image.

Black and white photograph of the Devil's Kitchen cave on Mackinac Island, Michigan. Two men and one woman are visible standing inside the cave.

Black and white lantern slide of a hand-drawn sketch diagram of canal lock systems.

Black and white lantern slide of a masonry dike along the Yellow River in China at high water.

Black and white lantern slide of a rocky riverbank and masonry dike along the Yellow River in China.

Black and white lantern slide of a dike on the Yellow River being closed.

Black and white lantern slide of crowds of people along a dike of the Yellow River in China.

Black and white lantern slide of a dike on the Yellow River with ropes connected from the dike down into the water.

Black and white lantern slide of a stone dike along the Yellow River in China. A small boat sits on the water near the dike.