After the vote to sell the old Army surplus jeeps, after the debate over whether to buy or lease a copying machine for the town clerk's office, Polly Mansell stepped to the microphone to speak to her fellow citizens about acid rain.

"We have to do something, or we won't have any lakes. We won't have any trees," she told the residents gathered in the school auditorium for Andover's annual town meeting. "The red spruce are going. The maple trees are already being affected. We have three lakes that have been killed. All you fishermen, and all you people who care about New Hampshire, I hope you vote for this."

The item under discussion was Article 9 on the town meeting "warrant" in this rural community of 1,500 some 30 miles northwest of Concord. Article 9 called on the federal government to control sulfur dioxide emissions from factories in the Midwest that are thought to cause acid rain and snow here.

Similar articles were on the warrant for town meetings this week in 193 of New Hampshire's 218 towns. And returns from the 101 towns that considered acid rain resolutions at meetings Tuesday night were solidly in favor of curtailing emissions.

Of towns reporting, 93 voted in favor of the proposal, many unanimously. Only one town decided to table the resolution, and five others, where acid rain was not up for discussion, added acid rain to their agendas and voted for the measure.

Resolution supporters hope to translate that concern into political leverage that might end the continuing congressional stalemate over proposals to limit acid rain. The issue already has drawn the attention of presidential hopefuls trooping through this key primary state.

The resolution called on the federal government to cut sulfur dioxide emissions by at least one-half by 1990.

But Joseph Dowd of the American Electric Power Co. said it was not clear that sulfur dioxide emissions cause acid rain. Dowd noted that coal-burning electric utilities had reduced emissions in six midwestern states by 15 percent between 1975 and 1980, but that the acidity level of rain in New England had not dropped.