Pressure Gage Record on Tree. From 9.30 a.m. to 8.30 a.m. Note the sharp rise from 2 pound s negative tension or suction at 9.30 a.m. to 12.5 pounds pressure at 11 and 20 pounds at noon, the slow fall to 15 pounds at 8.30 p.m. and the rapid fall to 25 pounds suction before 10 o'clock. This was a good sap day.

Digital Commonwealth — Boston Public Library

Pressure Gage Record on Tree. From 9.30 a.m. to 8.30 a.m. Note the sharp rise from 2 pound s negative tension or suction at 9.30 a.m. to 12.5 pounds pressure at 11 and 20 pounds at noon, the slow fall to 15 pounds at 8.30 p.m. and the rapid fall to 25 pounds suction before 10 o'clock. This was a good sap day.

[ca. April 1909]

RightsCC0 — Public Domain

CollectionDigital Commonwealth — Boston Public Library

[Information from item housing] Map & Mapmaking

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