For the 11th day, the jury in the political corruption trial of Maryland Gov. Marvin Mandel failed to reach a verdict today, leaving defense attorneys anxious while adding a touch of adventure to the Sunday strolls of Baltimoreans.

The jurors quit for the evening at 7:30 p.m. after passing the 100-hour mark in its deliberations four hours earlier. The jury is scheduled to resume consideration of the case at 9 a.m. Monday.

Defense attorneys announced today that they would caucus Monday morning to consider asking U.S. District Court Judge Robert L. Taylor to quiz the jurors about whether further deliberations might lead to a verdict. The attorneys also said they might consider at the caucus "the most extreme" request of asking the judge to declare a mistrial.

While these weightly decisions were being outlined to television, radio and newspaper reporters, dozens of tourists drifted by the federal courthouse here, either expecting news of a verdict or a glimpse of what someone called "the expensive commotion."

"No, I am not a tourist, I'm one of the ones paying for this," said Lewis Potash, a Baltimore engineer and taxpayer. Potash said he was here for "the most important aspect" of the case: "When the layman makes the decision, not the yoyos with law degrees.

"I think it's a good jury in there. They didn't make a decision right away," Potash said.

Taking pictures of television cameras taking pictures, cautiously venturing into the courthouse itself, the tourists - and the taxpayers - apparently found more excitement here than most courtroom observers and participants have felt since the jury began its deliberations Aug. 10.

Lillian Sobol, of Baltimore, watched five boys elbow aside a television correspondent in order to push their faces before a camera. "It's unreal. It's really very interesting," she commented before asking, "Is now when it happens, when the verdict comes in?"

The bank of television cameras spread across the courthouse portico apparently drew moss of the Baltimoreans from the nearby Hispanic festival at the Johns Hopkins plaza. They expected a verdict.

"I got excited, I think everybody wants to know about the verdict," said a disappointed Rita Byrd, also of Baltimore.

Most of the citizens outside the courthouse today had made up their minds about the governor but often not on the charges in the case.

"It's like a plot from a 'B' movie," said Daniel Jones of Baltimore. The engineer Potash said simply that "Mandel has been cut down to size - he doesn't buy his own suits. The longer they're out the more likely the verdict will be guilty."

Marvin Harris, another observer, disagreed. "He's a good man, an old friend who has done a lot for Baltimore. I think it's a good sign that the jury is taking so long.