Government agencies and advocates for the homeless now have a better idea of the size of the Cambridge homeless population thanks to the first-ever Cambridge homeless census, conducted earlier this winter by the city's Multi-Service Center for the Homeless (MSCH).

Figures which were released last week by the department revealed that 478 people were homeless in Cambridge on the night of Dec. 16, 1996.

"We needed to know this information to develop appropriate programs and services," said Len J. Thomas, director of the center, a branch of the Cambridge Department of Human Service Programs (DHSP).

The U.S. Bureau of the Census had counted 252 homeless persons in Cambridge in 1990, but the city believes that figure is an underestimate.

Thomas said the Cambridge homeless census was taken on the same night as a Boston homeless census to avoid double counting homeless people.

The Boston census counted 4,898 homeless people, including 183 on the streets.

The Boston census has been taken for the past 12 years, Thomas said.

The Cambridge count included 199 persons in individual shelters; seven women and nine children in a shelter for battered families; 32 families in family shelters; 72 persons in transitional housing programs; 76 unsheltered people; 13 men who were transported by van to Boston for shelter; and others in detoxification programs and hotels.

Thomas said it is impossible to characterize the Cambridge homeless population.

"I think there is sort of a common perception that all homeless are people who are inebriated all the time, and that is really not the case," Thomas said.

He said the count is likely an underestimate because only those homeless people who were visible were counted.

Due to the cold temperatures in December, Thomas said many homeless people had likely sought shelter in warm places out of sight of the counters.

"We didn't go into areas where there may have been safety concerns," Thomas said.

Thomas said his office plans to make the Dec. 16 count an annual event and conduct another one this summer, adding, however, that any such one-night count is only a "snap-shot" of the homeless population.

The 18 homeless men and five homeless women who spent the night of Dec. 16 at the University Lutheran Homeless Shelter, a program run by Phillips Brooks House Association volunteers, were among those included in the count, according to information obtained from the center.

University Lutheran is a 22-bed facility believed to be the only entirely student-run homeless shelter in the United States, said Stephanie M. Mayer '97-'99, the shelter's co-director.

The Cambridge count was conducted by three teams made up of volunteers from DHSP; street-out-reach staff from Bread and Jams and On the Rise, two local service providers; and staff from Professional Ambulance's cold-weather emergency programs, who also provided first aid