the mild temperatures and fishing. He bought property on the Caloosahatchee River. (“So many tarpon and other fish come up the shallow river,” Edison wrote a friend, “that it raises it 11 inches every season.”) He ordered two identical houses from a builder in Maine and had them shipped south on schooners. (The second house was for a friend and business partner with whom he soon had a falling-out.) In 1915, Henry Ford bought the property right next door.

As you drive into the estates, a huge banyan dominates the parking area; the tree was part of a botanical garden that Edison created to test plants for their rubber content. His house was closed for restoration when we visited, but we stood on the wide wrap-around porch and looked in the windows. (His wife Mina liked wicker, indoors and out.) We also visited the laboratory that Edison built so he could spend his vacations working. With its Bunsen burners and glass tubes, the lab struck Kevin, a chemistry teacher, as comfortingly like the one he used at college; I enjoyed seeing the cot where the great man took his naps.

Edison and Ford liked to take car trips into the Everglades; their wives would bring home orchids to plant in the crooks of trees on their property. During the week, there are guided tours of the gardens, and if you arrive early enough, you can sign up for a one-hour river cruise in a reproduction of Edison’s electric launch Reliance. The museum here displays some of the fruits of Edison’s labor: phonographs, Kinetoscopes, light bulbs of all shapes and sizes. “Opportunity is missed by most people,” Edison said, “because it is dressed in overalls and looks like work.”

The next morning, we set off for Sanibel, a half-hour drive from Fort Myers Beach over a small causeway. The island, 12 miles long and five miles across at its widest, is one of the few islands anywhere that is oriented east-west rather than north south, which means that currents in the Gulf of Mexico deliver shells right up onto the shore.

In pursuit of knowledge, we made our first stop at a place on the National Register of Historic Places, a Dairy Queen built in the 1970s. (Later, I discovered that my guidebook said simply that this place deserves landmark status; it was in place before Sanibel got tough about fighting development, and it’s the only fast-food establishment on the island.) Energized by chocolate Blizzards, we visited the 1884 lighthouse, an unprepossessing steel structure designed to allow high winds to blow right through it. (Hurricanes hit this part of Florida fairly often, blowing off roofs and ripping out trees, but the landscape manages to recover.) You can’t go into the two keeper’s houses (they’re occupied), so we wandered to a fishing pier a few hundred yards away, where exotic-looking snowy egrets were flapping at each other’s throats. Our best nature sightings were all like this one—unplanned.

In the afternoon, we checked into the

Island Inn, a cluster of small buildings on West Gulf Drive. We found we’d been given our own two-bedroom house right on the beach. "Matthews Cottage" read a wooden sign over the door; inside, the floors were yellow pine, the walls horizontal beadboard, the closets deep, the kitchen timeless, the slipcovers a pale celery floral and stripe that I wished I could take home. At night, we could hear the waves breaking on the shore. Having our own cottage was wonderful all by itself, but it also made us part of a century-old Island Inn tradition.

Will Matthews moved to Sanibel from Kentucky in 1885 to try farming; when that failed, he and his wife Hallie opened a boardinghouse that became known as The Matthews. In 1905, they built the cottage in which they would live; this is the one we were staying in, and it’s the oldest-surviving building on the 10-acre property. When her husband died, Hallie began offering longtime guests lots to build their own cottages on, as long as they promised to take their meals at her restaurant. The Matthews, later called the Island Inn, stayed in her family until 1957, when several loyal customers took over the operation. From mid-November to April, a chef prepares breakfast and dinner, and guests gather each night in the dining room.

Just outside our cottage door were a swimming pool and shuffleboard court, a wispy border of sea oats, and then the soft turquoise of the Gulf. The four of us headed to the beach, and the boys scattered. All along the fine white sand were vast puddles of shells: cockles and conchs, whelks and arks, thousands of iridescent pastel shapes the size of a dime or smaller. Drifts of sandpipers skittered in the surf, and a pair of white ibis looked calmly out to sea, unmoved by our arrival.

After a while, Dan wandered back in our direction. He was wearing a black T-shirt, and his head was hanging under the weight of his uncut hair. “He hates it here,” Kevin said. “He wishes he were back home, going to movies with his friends.”

“I love it here,” Dan said when he reached us, carrying a fragment of a conch shell the size of a gallon of bleach. “I’m so much happier when I’m warm.”

One rainy morning, we went to the Sanibel Historical Village and Museum, a collection of some of the island’s first buildings that had been moved to a site on Tarpon Bay and joined together by boardwalks. (Seeing the tiny post office gives you a sense of how remote the island was when it was accessible only by ferry.) You can visit three early cottages, including one called Morning Glories, a charming 1925 Sears, Roebuck house. Bailey’s General Store, built in 1935, is stocked with vintage magazines, extinct cereals, and cases of Coca-Cola in green bottles. The village has the island’s first schoolhouse, built in 1892, and a teashop that Hallie Matthews’s daughter, Charlotta, ran for many years. It

also has a good supply of knowledgeable and enthusiastic volunteers. A guide named Betty Fisher asked, “Boys, would you like to hear an old record?” Our sons obligingly removed the headphones from their ears. She cranked up an ancient Silvertone phonograph and placed the needle on a 78; Dan and Jim did their best to look appreciative.

About two-thirds of Sanibel is taken up by the J. N. “Ding” Darling National Wildlife Refuge, home to alligators, manatees, and more than 200 species of birds. The sanctuary is named after a political cartoonist for the Des Moines Register who worked hard for conservation causes around the country. Franklin Roosevelt eventually appointed him head of the U.S. Biological Survey (later, the Fish and Wildlife Service).

One morning, joining a tour conducted by Tarpon Bay Explorers, we kayaked through the mangrove swamp in the refuge. Brown pelicans perched on the trail markers, and we saw a rat snake hanging from a tree. Kayaks are stable boats, and paddling with the breeze behind you is almost effortless. Eventually, of course, the moment comes to turn around and battle a headwind back to the dock. “Take your time,” our young blonde guide suggested when our two-hour tour was up. Pointing off to the horizon, she said: “See those islands over there? We saw a manatee out there earlier today.” Suddenly, manatees seemed like no big deal.

Tarpon Bay Explorers also offers tours of the refuge in an open tram that stops wherever seabirds or alligators are likely to gather. I boarded the tram while Kevin rented a motorbike and took our underage drivers for a spin. No alligators appeared to those of us on the tour, but Kevin and the boys saw one sunning itself beside one of the canals that crosses the island. Experts suggest visiting Ding Darling at low tide, especially at daybreak, when birds are most likely to feed. Next time, I’ll consult a tide chart and set an alarm clock.

Around noon one day, we drove to Captiva, a smaller island just north of Sanibel. The sand is slightly rougher there (it was replenished recently), and the water is a brighter turquoise. Anne Morrow Lindbergh spent a week here without her husband or children in 1955. She rented a cottage, walked the beach, and went home to write Gift from the Sea, her classic meditation on solitude, marriage, and family.

We had lunch at the Bubble Room, a Captiva experience as unlike Mrs. Lindbergh’s as you could find. Every available square inch of the restaurant is taken up with memorabilia: Christmas decorations (including bubble lights), movie posters, old toys, jukeboxes, even an antique diving helmet. We ordered hamburgers and homemade potato chips, and our Cokes arrived in old-fashioned green bottles, each with a cherry on top. At the end of the meal, waiters dressed in Scout uniforms passed trays loaded with seven kinds of homemade cake, each hunk the size of a baseball glove. I could skip the costume, but not the

cake.

We hadn’t planned to bring home shells from Sanibel. Gradually, though, little piles began to accumulate on the steps of our cottage. A few wound up in our pockets, and, for weeks after we got home, I’d find a very clean shell or two at the bottom of the washing machine. Eight months later, from across the room, Jim heard me mention the word April. “Mom,” he said in a demanding tone that adolescence has done nothing to soften, “we’re going back to Sanibel.”