In a conversation about 20 years ago with someone from Philadelphia, I mentioned that I lived in Allentown. "Oh, I know Allentown," he said "Hess's, Dorney Park."

While Hess's is no more, Dorney Park, actually located in South Whitehall Township, continues to thrive bigger than ever. For some who remember the simpler park of the past, the change can seem a bit overwhelming. To keep the memories of the old Dorney young, writer Wally Ely and Robert "Bob" Ott, whose family was involved with the park from the 1920s to the 1980s, have put together a photographic history of the amusement mecca.

Called simply "Dorney Park" (Arcadia Press; $19.99; 128 pp.) it is a part of Arcadia's popular Images of America series, which are nostalgic histories of towns, cities, villages and other sites across the United States.

In his preface, Ely states that he and Ott and their wives are members of St. John's Lutheran Church in Allentown. They also worked together in the 1970s when Ely was president of the Allentown- Lehigh County Tourist and Convention Bureau.

It was in 2000, while filming a television spot with Ott about Dorney's Zephyr, the park's train ride, that Ely became convinced there was book in the park's past. Ott agreed to help.

Ely and Ott had a number of sources for pictures. Perhaps most important was Ott's own extensive photo file. Dave Bausch, former Lehigh County executive and current Allentown city councilman, offered access to his vast postcard and photo collection.

Carol Front, curator of the Raymond E. Holland Regional and Industrial History Collection, gave access to its extensive resources. Former Morning Call photographer Ken Clauser also contributed.

Dorney Park's roots go back to the 1870s and the entrepreneurial- minded Pennsylvania German farmer who started the park, Solomon P. Dorney. A photo of the bewhiskered gent is the first one in the first chapter.

The original Dorney was not about thrill rides. Visitors from hot, noisy cities strolled the grounds, stayed in the farmhouse- turned-hotel and ate trout from Dorney's fish weirs or ponds. Although simple amusements were introduced in 1884, not much had changed by the time Solomon Dorney died in 1901.

The park was then taken over by Solomon's brother, O.C. Dorney, who was an investor in the Allentown Reading Traction Co. Its rival, the Lehigh Valley Transit Co., was then making a fortune by taking its riders out to Rittersville's Central Park. Apparently, Dorney wanted some of that business. "And that's when Dorney Park really went into amusements," says Ott.

The grandaddy of amusements at Dorney was Jacob Plarr. He came to the park in 1904 to run the first merry-go-round, liked it, and bought the ride. According to Ott, Plarr put his wife in charge of the tickets and named his 9-year-old son, Bob (later Ott's father- in-law) as the ring boy. In the early 1920s, Bob Plarr took over Dorney Park. It stayed in the family until sold by Ott in 1985. Dorney, still at its original location off Hamilton Boulevard, is now owned by Cedar Fair LP of Sandusky, Ohio.

The book's chapters are divided by sections of the park.

Some will remember with fondness the swimming pool. From 1904 to 1964 it drew thousands hoping to beat the heat in those mostly air- conditioner-less summers of yore. A photo circa 1918 shows bathers in suits that covered most of the body. Over the pool is the Sellner Slide, a water slide ride that would be at home in today's Wild Water Kingdom.

Festive occasions by the pool are featured. A 1960 photo shows the First National Bank of Allentown's affair for employees. It was called an "Aloha Party."

Dorney got its first railroad ride, the Scenic Railway, actually a roller-coaster type contraption, before 1900. In the early 1900s a small steam train was added. The book features a picture of this puff-puff, toot-toot ride in 1920 with a young Bob Plarr at the controls.

But the real gem is the Zephyr, whose sleek Art Deco design echoes the era when train travel was a romantic adventure. Ott recalls that the Zephyr was created in 1934 by Miles "Mike" Ebor, a machinist from Wescosville.

The newspapers that year were full of accounts of the Burlington Zephyr, then being hailed as the train of tomorrow. Ebor's small- scale creation was an immediate hit. Ott claims it saved Dorney Park from going broke during the Great Depression. It has remained popular ever since.

Dorney's first real thrill ride was a roller coaster, now known as Thunderhawk. It was built between 1923 and 1927 for the park by the Philadelphia Toboggan Co. One photo features a long line of boys in knickers, white shirts and ties waiting to get on.

Dorney Park always had its romantic side. For many years, it was popular for its dance hall. The first dance hall, built in 1925, was known as the Al-Dorn, for Allentown Dorney. In 1935, the Al-Dorn was succeeded by Castle Garden. Among the most interesting items in the book is a photograph of part of a ledger page, kept by Bob Ott, listing the big bands that played from April 11 to June 30, 1938, at Castle Garden. Sammy Kaye, Benny Goodman and Louis Armstrong are on the list. Castle Garden was still going strong when it was destroyed by a fire in 1988.