An uncommon early mechanical speed indicator / revolution counter by the renowned German precision-instrument manufacturer Schäffer & Budenberg (S&B) of Magdeburg-Buckau, dating from around the turn of the 20th century. The instrument is clearly signed “S&B” on its engraved circular dial and is preserved together with its fitted period storage box. This compact hand-held instrument was designed for determining the rotational speed of machinery and shafts before the development of modern electronic tachometers. Its projecting spindle was placed against the end of a rotating shaft. Rotation was transmitted through the spindle and worm gear to the large toothed dial, allowing the operator to count revolutions over a measured period of time and determine the rotational speed. The mechanism belongs to an important early family of mechanical speed indicators derived from the principle patented in the United States by Daniel Davis Jr. and Edward Wright as US Patent No. 182,177, granted on 12 September 1876 for an “Improvement in Rotary Measures.” The patent specifically describes a speed indicator using a projecting spindle, worm drive and single graduated gear wheel – the same fundamental mechanical arrangement visible on this instrument. The original patent describes how the spindle was pressed against the shaft being tested and held there for a predetermined period, after which the revolutions indicated by the dial could be used to calculate the speed. Commercial versions of this principle later became widely associated with the name “Woodman’s Patent.” Schäffer & Budenberg itself had considerable expertise in this field. The company patented tachometer technology in Germany during the 1880s and subsequently manufactured a range of instruments for measuring and recording the rotational speed of machinery. Contemporary Schäffer & Budenberg advertising from 1906 specifically lists both “Tachometer” and “Handtachometer,” describing precision apparatus for indicating the revolutions per minute of rotating shafts. Historical Schäffer & Budenberg tachometers are also preserved today in the Science Museum Group collection in the United Kingdom. The present example is particularly attractive because of its unusually elaborate construction. Rather than the purely functional appearance of later industrial measuring instruments, the cast metal body incorporates decorative openwork and scrolling motifs, including the distinctive heart-shaped terminal. Raised polished elements contrast with the finely textured recessed surfaces. The circular metal dial has developed an attractive warm patina and carries a finely divided 0–100 scale with a blued-steel pointer. The exposed toothed circumference and worm-drive spindle provide an excellent view of the instrument's simple but ingenious mechanical operation. The fitted burgundy-coloured period box is also preserved. Its cream interior shows age-related wear and staining, while the exterior remains attractive and complements the instrument particularly well. Condition: Good antique condition with age-related wear consistent with its considerable age. The metal body retains an attractive surface with scratches, small marks, areas of oxidation and minor surface wear. The dial shows natural patination and colour variation. The engraved graduations and S&B maker's mark remain clearly visible. The decorative casting and mechanical components appear complete as photographed. The fitted period box shows normal wear, marks and staining, particularly to the light-coloured interior. No modern restoration or aggressive polishing has been undertaken. The instrument is offered as a historical precision instrument and collector's object; its measuring accuracy has not been professionally calibrated or certified. - Dimensions: approx. 10.5 × 5.8 × 2 cm - Weight: approx. 118 g An uncommon and visually striking survivor from the early history of mechanical speed measurement, combining precision engineering with the unusually decorative industrial design characteristic of the period. Particularly interesting for collectors of scientific instruments, mechanical engineering, industrial history and early measuring technology. Carefully packed for secure international shipping.