Both mothers began the Saturday Science program last year. They engage children by letting them “have fun and get dirty” while learning about lesser-known scientists, particularly women and minorities.

Two dozen children sat cross-legged and wide-eyed, eager to dig for “dinosaur eggs” buried in the dirt-filled plastic wading pools nearby. This was the February session of the Hingham Public Library’s “Saturday Science – Beyond Einstein,” a monthly event implemented and run by two mothers who share an enthusiasm for science. “We’re going to talk a little and then we’re going to have a lot of fun,” said “Miss Sonia,” attorney Sonia Steele.

“Who knows what a fossil is?”

Hands went up. “Right,” she replied to several answers. “Animal and plant fossils will help us learn about history and what happened before us.”

Miss Sonia wore an “I speak dinosaur” button. “Miss Katie,” pediatrician Dr. Katie McBrine, sported a dinosaur-print T-shirt.

Both mothers began the Saturday Science program last year. They engage children by letting them “have fun and get dirty” while learning about lesser-known scientists, particularly women and minorities.

The program usually meets at 10:30 a.m. on the first Saturday of the month during the school year. It’s geared for children in grades K-3. Kindergarteners are the most numerous and the boy-girl split is about even.

“Kids have such a sense of wonder,” Steele said. “Science is magic to them.”

Both women are “volunteers extraordinaire,” according to Totsie McGonagle, Hingham children’s librarian. “They pick the scientist, figure out the craft, bring the materials and donate their time,” she said.

The February session focused on the study of fossils. Research into the study of fossil brains (paleoneurology) was pioneered by German-American scientist Tilly Edinger.

“Tilly wore hearing aids because she was deaf but that never stopped her,” McBrine explained.

She and Steele delivered a quick lesson on four kinds of fossils -- trace, mold, cast and true form -- and showed drawings of each.

“Finding a ‘true form’ fossil is really, really lucky because then we can see what the animal looked like,” said Steele.

Meanwhile their volunteer assistant “Miss Morgan,” Hingham sixth-grader Morgan Sandler, circulated a tray of examples – corn starch and baking soda fossils pressed into Play-Doh lids.

When the digging was to start, ground rules were simply stated; we don’t throw dirt and we do share. Everybody gets to keep three fossils.

“I found one! I found another!” came cries from the sandboxes. Each egg, made of flour, sand and coffee grounds, held some type of crafted fossil.

McBrine helped one boy struggling to open his discovery. “You just crack it open, buddy. You hit it with your foot,” she said, crushing it with her boot.

More stomping and crunching followed. Steele’s husband Victor helped out while daughters Georgia, 7 and Norah, 5, joined in the action along with McBrine’s 5-year-old Samantha and son Gavin, 8.

An array of library picture books filled a nearby table so that youngsters could tell a Spinosaurus from a Polacanthus. A white board held a game to match picture magnets to printed dinosaur names.

“We try to keep the lesson fun and interactive for the kids,” said Steele. In past sessions they’ve used marble runs (physics), cupcakes (taste/smell), and built fairy houses (architecture.)

“We’ve also made neurons out of drinking straws, string, and bits of fabric,” she added “and studied the fabulous neuroscientist Marian Diamond, who carried around a human brain in a flowery hat box.”

In other sessions, children have made catapults and heard about Chien-Shiung Wu, a Chinese-American experimental nuclear physicist.

“We talked about Rosalind Franklin (a British scientist who contributed to the discovery of DNA’s molecular structure) and made candy DNA models,” McBrine added.

“Sonia and I both like crafting and science,” she explained. The two had struck up a friendship at the 2016 kindergarten orientation.

They were later inspired in part by reading “Good Night Stories for Rebel Girls," a children's book with 100 bedtime stories about the lives of 100 extraordinary women from the past and the present.

Saturday Science usually lasts an hour. One exception was a four-hour session in January using a Discovery Dome, a portable planetarium set up in the Cohasset Recreation Center with help from McGonagle and Sharon Moody, Cohasset children’s librarian.

Some support has come from local businesses: Sadie Mae’s (cupcakes for taste tests) and Starbucks (coffee grounds for dinosaur egg dough.)

“We’ve paid for most of the material, but the library has also helped,” Steele noted. “Maybe in the future we can apply for a grant.”

“We have some more great sessions coming up,” McBrine said, “including one about skin; the Children's Melanoma Prevention Foundation will be there.”

To enroll in a program, contact Totsie McGonagle, Hingham children’s librarian, 781-741-1405, tmcgonagle@ocln.org.

Gail Besse Ryberg is a regular Hingham Journal correspondent.