The telephone was ringing off the hook in the wood-paneled business office. Outside, the warehouse foreman was supervising a dozen burly workmen loading and unloading truckloads of pornographic magazines.

"This business beats on you," the prespiring foreman said after returning to his office. "A coal miner has it easier than I have. We all work like hell because we love it. Every minute of it."

It was a typically busy day at one of the three large Baltimore warehouses operated by what police say are the principal wholesale distributors of pornography for "adult" bookstores in Washington and the Middle Atlantic states.

The businesses located in the three warehouses rank among the nation's top pornography peddlers, with combined annual sales exceeding $10 million, according to police estimates. The highly lurcative trade yields an estimated $5 for every $1 spent.

In the argot of law enforcers, the three firms occupying the warehouses form "The Baltimore Connection" for regional distribution of sexual materials produced in California or abroad and funded trhough other wholesale dealers in New York and Cleveland.

From their simple exteriors, the buildings occupied by Bon-Jay Sales Inc., Noble News Company Inc. and Central Sales Inc. look like many of the dry goods and produce warehouses that surround them in industrial sections of East Baltimore.

Inside these warehouses, however, lies the well-stocked arsenal of erotica for scores of "sex shops" in the District of Columbia, Maryland, Virginia, Delaware and North Carolina. Police say the three companies account for 85 per cent of the pornography in Washington area shops.

For the retail bookstore operator who shops at the three Baltimore houses, there is a vast array of carnal wares ranging from inflatable plastic "sex dolls" to multicolored lotions promising to enhance sexual pleasures.

Films and written materials confiscated in past raids varied in taste from the so-called soft-core magazines found on drugstore shelves to hard-core displays of child pornography, incest, bestiality, scatology and homosexuality, police say.

In a recent visit to the Central Sales warehouses, a reporter saw thousands of magazines neatly stakced on metal racks, upturned cardboxes filled with marital "aids" in various sizes and shapes and scores of film cartridges. Several dozen boxes of pornographic plastic Santa Clauses were being prepared for shipping during the holiday season.

Down a narrow hallway, a short, muscular man named Lousi Guglielmi, who manages the warehouse, at a large desk answering telephone calls from customers. A record album featuring Xaviera Hollander, known as "The Happy Hooker," was propped on shelves behind his desk.

"Some customers send in detailed requests or say, 'Send me group nude or single male,'" Guglielmi explained between calls. "If we call, I'll ask him if he needs anything. Magazines, rubber goods, whatever. He'll ask me what I've got that's new. You're always looking for something new."

"I run a clean house," he said."Everything that comes in here I look at. I'll look page for page. If II see anything I don't like, I pass on it. I draw the line. This looks on the young side; OK, pass. Animals are out, out, out. Bondage, only if it's done in good taste. When you go in with blood and all that stuff, that's sick."

Until recently, very little was known about Baltimore's three wholesalers. They set up shop in nonresidential areas and under innocuous-sounding names and operated quietly. Except for Bon-Jay, they are owned by out-of-state corporations.

In the past two years, however, Maryland State Police and federal law enforcers, following a national crackdown on big pornography dealers, began intessive investigation of Baltimire's "Big Theree.'"

What emerges from a study of the court records and interviews with law enforcers and the distributors themselves is the picture of a highly-secretive well-organized industry that uses conventional techniques of big business to prosper.

"If you're looking for a method of operation," observed a federal officer involved in pornography investigations, "I don't think there's anything mysterious about this business. If you asked how to move lady's cosmetics, it would be the same thing."

Each distributor is said to send customers catalogues and brochures featuring new products, often offering discounts for large purchases. One such brochure offered a 10 per cent discount for purchases of rubber goods larger than .75.

The distributors extend credit to trustworthy customers and size up a market through informal surveys. For example, the District fo Columbia is known as a "fast town" tolerant of the sex industry, whereas Norfolk supposedly is conservative and open only to soft-core pornography.

Warehouse "salesmen" driving panel trucks travel to bookstores in the District of Columbia and other cities on a daily basis, distributing products lists, taking orders and delivering merchandise.. Sometimes they sell items right off the backs of their vans.

Long-distance orders are taken by telephone - Bon-Jay reportedly had two national WATS (Wide Area Telephone Service) lines in use during a police raid in 1976 - and sexual materials are sent by mail, panel trucks, United Parcel Service, airplane and train, police said.

A "regular" customer can roam through the warehouse and select pornographic products in person. The firms keep detailed "customer lists" and admit persons through their locked doors only after careful screening.

One of the customers at Central Sales recently was Ira Adler, a long-time porno purveyor who owns nine bookstores in Delaware and the Baltimore area. Adler, who said he plans to open a shop in the District of Columbia, discussed his wholesale transactions.

"I go to Central, Louis (Guglielmi) gives me a bill, our bill is recorded and we pay taxes," Adler explanined. "We operate like any other normal business. If we buy bad magazines, we try to discount them. If we won't discount them, we 'eat' them."

Most pornography sold wholesale in this region originates in California, police say, although there is evidence that some erotica is smuggled into this country from abroad and reproduced here in larger volume.

When Maryland State police raided the Noble News warehouse in 1976, they said they found negatives of pornographic prints inside the hollowed-out section of a French art book. Next to the book was some wrappinmg with a Netherlands postmark.

"You have certain porno stars who get their advertising through the movies," explained a warehouse employee. "If they happen to be in a magzaine, it's got to go. They sell because the people in them sell. If the price is right. I'll buy them."

The wholesale pornographer with the largest trade in the Washington area is Bon-jay, police say. More than half of the erotica that reaches the District of Columbia comes from that large warehouse in one of Baltimore's modern industrial parks.

The man identified in corporation papers filed with the state in 1975 as Bon-Jay's sole stockholder, Jack Greser, is said to own at least five bookstores and a gay movie house in the District of columbia in addition to his lucrative wholesale distribution.

Baltimore police raided Bon-Jay in 1976 and said they found more than $1 million worth of merchandise. More than 143,000 separate items were in the spacious stockroom where cartons were piled 10 high.

A small storage room held multiple copeis of about 400 films with such titles as "Animal Lovers" and Lolly Pops" while another part of the warehouse was devoted to manufacturing and repair of peep show booths, according to investigators, who said that $2,828 in quarters was seized.

Police took two days to inventory goods seized in the raid, which included $2,828 in quarters apparently taken from peep show booths, and paper-back books, among them those entitled "Women Who Seduce Their Sons" and "Lesbian Enema Tricks."

For Gresser, Bon-Jay is the central spoke in what police describe as a far-flung financial empire that in recent years has encompassed real estate, bookstores, peep show booth manufacturing and a travel agency in the Baltimore area and publishing firms in New York. Bon-Jay enjoys sales of about $3.5 million a year, according to investigators.

Gresser, who faces charges of maintaining a comman nuisance and conspiracy to violate Maryland obscenity laws as a result of the 1976 police raid, refused to grant an interview for this article.

The Noble News warehouse is a one-story red brick structure not far from Interstate 95 in east Baltimore County. The windows are covered with blinds and the warehouse is not identified with a sign. Visitors must ring a bell and identify themselves through an intercom system before entering.

The quiet outward appearance belies an active interior. So active, police say, that Noble News services as many as 50 bookstores in this region, with the heaviest concentration in Virginia, North Carolina and the Baltimore area. Its film room allegedly contained as many as 3,000 hard-core movies in 1976.

According to court records relating to a 1976 police raid, Noble News is a land-based outfit reputed to be the largest pornography clearinghouse in the country. Sovereign distributes materials to all 50 states and the District of Colubia, police say.

The man publicly associated with Sovereign News, Reuben Sturman, is not a member of an organized crime family but has some connections with mob leaders, according to published reports and independent sources.

It was impossible to reach a representative of Noble News or Sovereign News for an interview.

Central Sales has the distinction of being Baltimore's oldest extant wholesale house, dating back to the middle 1960s when it was owned by Samuel Boltansky, once regarded by law enforcement officials as a major importer and distributor of sexual materials.

Members of the industry willing to discuss their views publicly say police try to portray the pornography business as part of organized crime to help justify enforcement of unpopular, unworkable and unconstitutional antiobscently laws.

"I'm not saying they should leave this business alone," Central Sales Guglielmi said. "I'm saying how the hell can they allow pot and booze and fights and killings? Where's the priority here? That porno book don't kill anybody.

"What's wrong with people looking at some pictures? We don't force nobody to buy it. People have the right to buy what they want. Tell me what's wrong with that? This is the adult business for adult people," he said