Seth Thomas Size 6s Model 18: Overview & Production

The Model 18 was introduced as the "Century." Material catalogs designate the following serial block for the Model 18 production: 950,001-1,000,000. However, because these blocks were designated prior to publication in 1904, it does not include all Model 18 movements. The Model 18 movements were fitted with flat hairsprings and omitted the safety pinion. Thus, none of the movements carry the "Safety Pinion" marking. Additionally, the material catalog provides a lenthy list of parts for the Model 18, suggesting this model was overhauled in a more complete manner compared to the incremental adaptations from the Models 15-17, likely to create an inexpensive movement the company could sell in a increasingly competitive market.