Alexander Calculating Machine
date: label: date made
content: 1864
name: label: patentee
content: Alexander, Joseph B.
label: maker
content: Alexander, Joseph B.
notes: label: Description
content: This is the U.S. Patent Office model for a lever-set non-printing adding machine. It has a wooden case with a curved metal front and back, and somewhat resembles an early cash register. It contains eight cogged wheels that rotate vertically on a common crosswise shaft. Each wheel is linked to a lever that extends from the front of the machine and is rotated upward to enter a number. The digits from 1 to 9 are stamped on the front of the case next to the opening for each lever, to indicate the digit being entered. Each large cogged wheel is linked to two smaller wheels. One turns forward, and gives the total entered. The second rotates in the opposite direction, and indicates differences. Each of the small wheels has the digits from 0 to 9 indicated around the edge.
label: Description
content: The results recorded by these wheels are visible through two rows of windows at the top of the case. Each of these windows has a hinged cover. Every tenth tooth on a large wheel has a spring cog that drives the adjacent wheel, causing carrying and borrowing as needed. Multiplication is carried out by repeated addition. A row of keys at the front of the machine is used in division. There is a crank on the left side for zeroing the wheels associated with these keys. There is supposed to be a zeroing crank for the upper wheels, but none is on the model.
label: Description
content: The machine is marked on the front at the base: IMPROVED CALCULATING MACHINE (/) INVENTED BY DR. J.B. ALEXANDER. It is marked on a paper tag attached to the left side: J.B. Alexander (/) Calculating (/) Machine (/) Received (/) 17th Decr (/) ‘63.
label: Description
content: The physician Joseph Bell Alexander was born in North Carolina in about 1823. When he patented this adding machine, he was living in Baltimore. Alexander then moved to Washington, D.C., where he took out several other patents before his death in about 1872.
label: Description
content: Reference:
label: Description
content: Joseph B. Alexander, “Improvement in Calculating Machines,” U.S. Patent 41898, March 15, 1864.
label: Location
content: Currently not on view
place: label: place made
content: United States: Maryland, Baltimore
label: place patented
content: United States: Maryland, Baltimore
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Adding Machines
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content: Science & Mathematics
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.309340
label: accession number
content: 89797
label: catalog number
content: 309340
objectType: label: Object Name
content: adding machine
label: Object Type
content: Patent Model
physicalDescription: label: Physical Description
content: copper (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: paper (overall material)
label: Physical Description
content: wood (overall material)
label: Measurements
content: overall: 20 cm x 14 cm x 19 cm; 7 7/8 in x 5 1/2 in x 7 15/32 in