This lab shows the spiral path followed by a positively charged particle (in red) in a uniform magnetic field. Also shown are the two components of the motion. The purple path shows the circular motion of the particle, coming from the velocity component that is perpendicular to the magnetic field. The black path shows the constant-velocity motion associated with the velocity component that is parallel to the field. The combination of the circular motion and the straight-line motion produces a spiral. Knowing that the particle is positive, you should be able to determine the direction of the magnetic field.