Post Office Inkstand with Sengbusch Inkwells

This US Post Office Department Postmasters glass desk set is a utilitarian piece of American postal history, designed specifically for government use.

Base & Construction

• Material: The heavy base is crafted from thick, light green glass with a distinct “coke-bottle” tint.
• Design: It features an oval-shaped, tiered design with two deep, circular recessed wells specifically molded to hold Sengbusch inkwells.
• Integrated Pen Tray: A long, shallow pen rest is carved into the front of the glass block for easy access during administrative tasks.

Sengbusch Self-Closing Inkwells

The set is equipped with two specialized Sengbusch marked inkwells, known for their “self-closing” safety design.

• Official Branding: Each glass inkwell features a collar embossed with “POST OFFICE DEPARTMENT” in block lettering.
• Patented Mechanism: The black hard-rubber or Bakelite tops are marked “SENGBUSCH” and “U.S.A.”. These tops utilized a gravity-fed plunger system that opened when a pen was inserted and automatically sealed when removed to prevent ink evaporation.

Historical Significance

These sets were standard issue for Postmasters and high-level clerks in United States Post Offices during the first half of the 20th century. The massive glass base was intended to be virtually indestructible and heavy enough to remain stationary on a busy service counter.

Manufacturing Era: Circa 1920–1930

Based on the patented features and the branding observed in the images, this set most likely dates to the early 20th century.

• Inkwell Patent Origins: Gustav J. Sengbusch received his primary patents for the “self-closing” inkwell mechanism between 1902 and 1915. The specific hard-rubber tops marked “SENGBUSCH U.S.A.” were the flagship product of his Milwaukee-based company during this timeframe.
• Government Branding: The embossing of “POST OFFICE DEPARTMENT” on the collars refers to the cabinet-level department that existed before it was reorganized into the U.S. Postal Service (USPS) in 1971.
• Glass Material: The thick, light green “slag” or “bottle” glass used for the base was a standard material for heavy-duty office equipment in the 1920s, providing the necessary weight to keep the stand from sliding on marble or wooden postal counters.

Distinguishing Features

• The “Self-Closing” Top: The black rubber assembly is designed to be airtight; the central plunger only depresses when a pen nib is inserted, a feature Sengbusch marketed heavily to government offices to reduce ink waste through evaporation.
• Base Design: The base is a “Double No. 51” model, specifically molded with two deep reservoirs and a single pen groove to accommodate a high volume of clerical work.