The task: create a structure to move a marble from above a table to the bottom. The supplies: a box containing toilet paper rolls, rulers, paper, pipe cleaners, tape, string, foil and more. The catch? Speed is the enemy: the more time it takes the marble to reach the end, the better.

Agilent Technologies hosted 115 girls ages 11 to 18 Saturday in the 11th Introduce a Girl to Engineering Day at the Santa Rosa campus, with engineer coaches to advise the girls on their "marble run" projects.

"It doesn't have to be beautiful; it just has to work," Katie Blake, an eighth-grader from Walnut Creek, told her team as she positioned a small cardboard ramp. "We can beautify it later."

The event, sponsored by the Women's Leadership Development Network at Agilent, encourages girls and young women to pursue STEM careers, or those in science, technology, engineering and mathematics.

Agilent engineer Monica Harrison said when she graduated in 2001, women made up about 10 percent of those in engineering careers nationwide.

"Today, it's only 11 percent," she said. "The rest of the world is at 30 or 40 percent. We're really behind. It's shocking.

"There is such a need for these kinds of projects," she said. "It gets girls interested in the STEM fields."

The morning kicked off with a keynote address by Debbie Senesky, a professor of aeronautics and astronautics at Stanford University and a mom to a 3-week-old infant.

Senesky, a mechanical engineer who earned her master's and Ph.D. from UC Berkeley, leads a team of researchers who design "teeny tiny mechanical components you can't see with your own eye," she told the girls.

She advised the students to find encouraging mentors, be mentors to others and not to be afraid to take things apart.

"That was something I did when I was very, very young," she said. "Through that, you learn how things actually work."

And take risks, she told them.

"There may be times that you don't feel like you belong or are out of place," she said. "But it's OK to stand out in a crowd and get out of your comfort zone."

Laura McCarter, president of the Women's Leadership Development group at Agilent, advised her team as they built ramps from foil and toilet paper rolls, with egg-crate cups to slow the marble on its descent.

"Women want to see a group come together and succeed," she said, as her four team members talked about how to keep the marble rolling slowly. "We're good at resolving differences of opinion and keeping on track to get to a final solution."

The winning marble run, made by "Einstein 2," incorporated a large paper funnel at the top, with foil ramps that looped several times around the flattened supply box, before the marble popped out the bottom 25 seconds later. Many other contraptions dropped the marble out after about 12 seconds.

(You can reach Staff Writer Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com.)