With the largest census in U.S. history less than six weeks away, the maze of local census offices on Rte. 1 in Fairfax County was almost empty one Thursday afternoon.

The 18 census employes working in the offices were engaged in a variety of activities -- pasing out copies of a newpaper column on male chauvinism, laboriously drawing "no smoking" signs, gazing at colored pins on a map. One worker , alone in a black room, was hunced over what appeared to be thousands of index cards and computer printouts.

Each of these 18 people is a political appointee earning a minimum of $5.50 per hour. Starting in mid-April, they will coordinate the government's efforts to count its citizens.

With the passage of the Civil Service Reform Act last year, these temporary, once-a-decade jobs became among the small percentage of government posts that can be legally filled by political patronage.

In late September, President Carter announced he would be keeping a close eye on fellow Democrats in order to "help his friends." In the political world the message was clear: Endorse Carter and a cut of the political largesse was yours.

At the same time, the president said the patronage would be spread around this time. Instead of relying only on recommendatins from members of Congress, he said, state and local officials would be encouraged to submit names to the Census Bureau.

That change enabled Lt. Gov. Charles S. Robb -- a Carter supporter -- to recommend Mary Jo Horan, a Fairfax County Democrat and wife of District Court Judge Richard (Butch) Horan, for the district supervisor's slot in the census area encompassing part of Northern Virginia. The pay is nearly $400 a week for the 10-odd months needed to count Northern Virginians.

Even though Horan agrees that the chances of seeing a Kennedy or Brown button in a census office are slim, she contends the method of appointments is an effective one.

"Please don't say we are political referrals; the Census Bureau can turn down any name it gets.

"Actually, with political referrals we get very good people. They are usually very civic-minded."

In spite of the preference being given Carter friends, Horan insists there will be plenty of temporary work available in Northern Virginia to hose who are not well connected politically.

Members of the Fairfax County Board of Supervisors are being asked to recommend people for the temporary jobs. Not surprisingly, the supervisor Horan mentioned was Vice Chairman Martha Penino -- a Demcrat who led the four other Democrats week.

"A recommendation from Martha (Pennino) would be nice," agrees Horan. "But by no means is that the only way to get hired.

"This office alone will need about 530 workers. There are 409 offices around the country and all together they will hire 275,000 employes.

"We'll be needing about 135 office clerks and about 400 people in the field. There is a good chance we are going to employ just about everyone who passes the test."

The test is a relatively simple multiple-choice exam given to all potential employes, including the political appointees.

Horan estimates that the number of workers the Fairfax office will need, coupled with those being sought for the larger Arlington Census Bureau, will total nearly 1,300.

Most of the jobs will pay $3.55 to $4 an hour, Horan says, and many will last just three to six weeks.

The pay and the temporary nature of the work, Horan says, makes recruitment in the Washington area more difficult than elsewhere.

"In other parts of the country that is not bad pay," says Horan. "But in this area, where the standard of living is so high, the money is not a big enticement."

Census officials say the 1980 census is the first to be done almost exclusively on a mail-out, mail-back basis. Census forms will be mailed March 28, and respondents are asked to return the completed forms by April 1, Census Day.

Several weeks later, the temporary workers will spring into action. Armed with lists of households that have not responded, they will go into the communities, urging people to return their forms.

According to Horan, the "enumerators," as they are called, need only to be able walk up and down stairs to be considered physically fit for the job. Applicants should be at least 18 years old -- if they are under 18 they must have a high school diploma -- and the only adults not eligible for employment are retired civil service employes.

"We're also looking for people who speak Spanish, Korean and Vietnamese, to help some of the people in our area who don't speak English to fill out their forms," Horan says.

One concern of many citizens has been whether the census information they provide will be confidential. By law, Horan says, it is.

"Even if we turn up the FBI's Ten Most Wanted list, we would not give that information to the FBI," she says. "Everything is secret and every census worker takes an oath of confidentiality."

Horan says the Census Bureau is proud of the fact that no census worker has ever been accused of revealing confidential information.

"There is a distrust of government out there to some extent, but it is important for people to know that not only is the census used to determine reapportionment in Congress, but also a lot of state and federal aid is based on population trends turned up by the census."

The census will be studied to trace trends in American life, such as the number of people livig in "boats, vans and tents," the number of houses without indoor plumbing and the percentage of unmarried couples living together.

According to Horan, the Census Bureau has declared one day in April "motel day," when enumerators will visit hotels and motels in an attempt to count people who are traveling during April.