Chickering's Use of Case Numbers

Case numbers (also referred to as assembly numbers or factory numbers) are applied to various parts of a piano before it is assembled so that the correct parts can be fitted to the correct “case” (the general frame for the piano).  Serial numbers, by contrast, were only applied after the piano was completed (or in some instances shipped).  Not all manufacturers embraced this practice, but by 1850 or so, Chickering did.  While Chickering’s serial numbers generally appear only once per piano, case numbers appear in numerous (usually not prominent) locations.  Additionally, unlike the serial numbers, which were applied chronoligically and not reused,1 Chickering’s case numbers do not appear to follow any order and were recycled. 2  Finally, Chickering's case numbers are always 3 or 4 digits.  This causes the researcher mistaking the case number for the seral number--a common occurence-- to believe the piano is decades older than it is. 

1.  An exception to this was Chickering's use of a 15,000 serial number series to the Scales 131 and 141 and possibly other 1920-30s-era concert grands.  Although theories abound regarding the meaning of the 15,000-series numbers (e.g. that a leading or trailing number was intentionally omitted, or some portion of the number is an abbreviation of its date), it is our belief that  Chickering simply applied this separate chronological series for its concert grands, which began to occupy an ever decreasing share of its output.  These numbers appear to fall within their own chronology (alongside the 120,000-160,000 series of contemporaneous pianos) and are indeed duplicates of serial numbers applied to pianos around 1854-55.  This, too, causes occasional gross misdating of these quite modern concert grands. 

2.  While the sales ledgers identifying Chickering's serial numbers and description of the corresponding piano and shipment date are extant, no separate logs for case numbers have been located.  Only after about 1902 did the sales ledgers also begin to include the corresponding case number for each piano.