This article introduces the OrthoZoom Scroller, a novel interaction technique that improves target acquisition in very large one-dimensional spaces. The OrthoZoom Scroller requires only a mouse to perform panning and zooming in a 1D space. Panning is performed along the slider dimension while zooming is performed along the orthogonal one. We present a controlled experiment showing that the OrthoZoom Scroller is about twice as fast as Speed Dependant Automatic Zooming to perform pointing tasks whose index of difficulty is in the 10-30 bits range. We also present an application to browse large textual documents with the OrthoZoom Scroller that uses semantic zooming and snapping on the structure.