Lasico 2000-V Square Root Planimeter


This analog instrument uses integration to find the average of the square roots of all the radial distances from the zero circle to the record line on a circular chart. It was particularly useful for calculations of rates of flow and total flow of liquids. The planimeter has a 4" black plastic arm with an adjusting screw and tracer lens; a 6" curved metal arm with a mounting screw and a slotted follower that is inserted in the chart board; and a white metal recording unit with white plastic measuring wheel and vernier and a metal registering dial. The recording unit is marked: LASICO (/) USA. Underneath the curved metal arm is a serial number: 97661.

A black plastic case is lined with black and red foam padding. A label inside the lid is marked: DESIGNED AND BUILT BY (/) MAXIMILIAN BERKTOLD, CALIFORNIA – USA. An extra tracing lens is inside the case. The bottom of the case is marked with the recycling symbol around the number 2 and above the letters HDPE. The instrument was received with instructions, 2011.0043.01.01.

Georg Lory (1897–1968) worked for several German instrument manufacturers, including R. Reiss, before he immigrated to the United States in 1925 and worked for the Eugene Dietzgen Company in its San Francisco office. In 1929 he established the Los Angeles Scientific Instrument Company in Los Angeles. He repaired and made equipment including surveying instruments, planimeters, and pantographs. In 1944 he applied for a patent on the square root planimeter, receiving it in 1949. According to the donor, who joined the company in 1950, this example was made in 1990 as model 2000-V. It sold for $865.00 and was intended for use with Foxboro Chart 898418. For an earlier example, see 2011.0043.02. Lasico closed in 2008, although Absolute Accuracy, a successor firm in the same location, continues to distribute models 10, 20, and 30.

The instrument reached the Smithsonian in 2011.

References: Georg Lory, "Square Root Radial Averager" (U.S. Patent 2,458,009 issued January 4, 1949); accession file.

Date Made: 1990

Maker: Los Angeles Scientific Instrument Company

Location: Currently not on view

Place Made: United States: California, Los Angeles

Subject: MathematicsEngineering


See more items in: Medicine and Science: Mathematics, Planimeters, Science & Mathematics


Exhibition Location:

Credit Line: Gift of Maxmilian Berktold

Data Source: National Museum of American History

Id Number: 2011.0043.01Accession Number: 2011.0043Catalog Number: 2011.0043.01

Object Name: planimeter

Physical Description: metal (overall material)plastic (overall material)foam (overall material)Measurements: overall: 5 cm x 32 cm x 16.1 cm; 1 31/32 in x 12 19/32 in x 6 11/32 in


Record Id: nmah_1401493

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