A measurement is reported of individual bubble locations along tracks of high‐energy protons in a very small, short time scale pentane bubble chamber. Track distortions of the usual kind are greatly reduced in this system, so that one is measuring, to a precision of a few microns, the deviation of the true centers of the bubbles from the particle path. The average deviation in bubble position measurement is found from second differences to be 3.8 &mgr; in space, most of which is shown to be accounted for by measurement errors. The average bubble is thus found to be centered on the track to better than 4 &mgr; in hydrocarbons; however, an occasional bubble will be off by many times the average deviation. Arguments are advanced to show that a similar precision should obtain in hydrogen. This result is shown to be in general agreement with the bubble‐chamber theory of Seitz.