"After the iron furnace closed, that was the end here," William Leap said. "Everybody just left the town."
Before him, a mound of dirt sat like an overgrown, 20-by-20-foot cairn surrounded by pine trees and a green chain-link fence. Behind the fence, running down the side of a hill, the catalpas lay gnarled and grotesque in early spring, entwined in the thin arms of an ancient vineyard.
"Everything's gone," Leap said.
Leap had been clearing tree-branches from the sand-and-gravel roads that fork, and fork again, and yet again, burrowing into the Wharton Tract of the Pinelands National Preserve.
Never, in Martha's short existence, were the straight-backed pine woods and rustling cedar swamps less than an elbow-length away from the 1,000 men and women and children who lived in those years a full day's wagon ride from Philadelphia.
Now that the old town is long abandoned, the woods have overtaken Martha. And Leap was busy clearing what might be called a historical path.
He was preparing for the first spring tour he gives, just about annually, for some organization or other through some of the ghost towns in the Pines.
Leap is a historian; a gregarious, self-taught, 60-year-old resident of Runnemede who has been roaming the sandy trails of the Pinelands since he was a boy, when his father bought a cabin in Browns Mills.
His career as a historian began, although he didn't know it then, one day in his early wanderings when he chanced upon the old Hanover furnace, half- buried and in ruins, in the woods.
"From the age of 6, I never knew what it was until I was over 25," Leap said. "I found out what it was when Arthur Pierce came out with Iron in the Pines."
That started him: Reading, researching, lecturing, and sharing his enthusiasm for the overgrown cellar holes and bog-iron headstones and carnivorous plants that New Jersey has inherited along with the the delicate, necessary ecology of South Jersey's Pinelands.
"There's a great romance about the pines, a great mystery," Leap said.
"The mystery of this is: At one time, this was the industrial heart of the United States. And it's all gone," he said. "There's nothing left."
When Isaac Potts shut down his furnace at Martha in the early 1830s, for instance, Potts and his workers abandoned a large log barn, frame houses with cellars, a mansion house, a school house, a hospital, 150 peach trees, 600 apple trees, the catalpa trees, the vineyard, the furnace.
But in the early 1970s when the National Park Service came to the site, they explored overgrown woods and crannies. Park service workers unearthed the furnace from a century of woodland debris, and found it intact.
They took photographs and made a catalogue of the artifacts.
Then they covered everything up again.
They left the chain-link fence behind.
"That's just to keep people from taking things away, a brick at a time," Leap said.
Now retired from his sign-painting business, Leap spends much of his time examining clues to that great mystery that is our past.
He sifts through local legends, documenting who-owned-which-tavern, debunking bogus local myths, and talking a blue streak all the while. He talks about the Jersey Devil, the National Park Service, the sand roads he's been stuck in, the time he drove straight across a cornfield, the tours he's led - he once lost 56 cars out of about 90 when someone in the caravan made a wrong turn - and Henry Beck, an older local historian who died in the late 1960s, and took his Pinelands expertise with him.
"Henry Beck died, and I got forced into the tourist business," Leap said.
His Pinelands tour, a daylong, maximum 15-car caravan, is popular. Very popular. It is so popular that this year's tour, which is scheduled for Saturday, was sold out a day and a half after it was first publicized.
Leap scheduled another tour, for May 13. That tour was sold out in another day and a half - without any publicity.
He scheduled a third tour, for Oct. 7. That tour is sold out.
He scheduled a fourth tour, for Oct. 21. There are only a few slots left.
Originally, Leap led the tours on behalf of the Audubon Wildlife Society, a nature group. Those were bus tours, and they became, in his words, "such a hassle," that he cut them out in the early 1980s.
Then, in 1984, he agreed to conduct car tours for the Rancocas Nature Center, which needed money.
"This year they sort of got on their feet financially," he said, and then he paused. "And they didn't ask me."
But the Camden County Historical Society did.
This year, Leap's tour will travel through 11 stops, from the outskirts of the Lebanon State Forest through the old Harrisville site, past the empty field and parksite that was once Bodine's Tavern, and on along the winding labyrinth that leads to Martha - a place deemed "unaccessible" on tourist maps - passing cedar swamps and pigmy pines and fire-swept treelands.
He will move through Martha and head for Washington and the clearing there that white settlers carved during their tenure, moving on to a cemetery where more than a century's winds and rain have rusted pin holes into its handful of bog-iron gravestones.
On that tour, Leap will tell his followers about "Peg-Leg" Webb, who first started cultivating cranberries for the Navy. He will tell them about the Civilian Conservation Corps, which worked in the Pinelands once. About the glaciers that swept through South Jersey, and the old ocean bed that now encrusts the Pinelands.
If he remembers, he'll tell them about Ogden Nash's cabin, isolated in the pine woods, and Nash's guest book, still hidden in a well, and he may quote Nash's quip:
The trouble with a kitten is that
It turns into a cat.
He will probably chuckle, at least once. And warn every visitor he takes to those sites: "The only thing we take with us when we leave are memories. And the only thing we leave behind are footprints. . . ."