In 1862 Carl Christian Plath purchased a small established German navigation instrument store founded by David Filby, a professional precision instrument maker, 25 years earlier. This company checked and certified sextants, barometers and compasses aboard ships in North Germany and also hand-built these instruments one by one. Plath broadened the base of the former Filby business. In 1865 Plath purchased a circular dividing machine for engraving the graduations on the arcs of the sextants he was producing. Soon Plath was manufacturing a broad line of nautical instruments, including compasses of all sorts, his newly patented lightweight compass card, patent logs, sextants and octants. In 1889, at the Hamburg Crafts and Industry Exhibition, Plath received high praise and a Gold Medal for excellent precision work and the best made instruments in Hamburg.
In 1899, Carl Plath's son, Theodor, became a partner in the family business. At this time, it was no longer efficient to produce sextants with the old circular dividing machine which Carl had purchased in 1865. Theodor was instrumental in developing a new electrically operated dividing machine which saved hours of manual labor and improved the accuracy of the sextants that were produced. The world reknowned C-Plath sextants were manufactured on this machine until World War II.
Together, Carl and Theodor, showed and demonstrated their precision instruments at the Paris World Exhibition in the German Shipping Pavilion in 1900. The exhibition jury presented C-Plath a silver medal, conferring upon them, "the highest distinction for nautical instruments in commercial shipping." This achievement cemented the exceptional reputation of C-Plath products throughout the world.
The early 1900's was a period of experimentation in aviation, and C-Plath was approached by pioneers in this field to develop a compass with a rotatable ring marked in degrees from 1 to 360 that would determine drift and the necessary correction angle . This new easy-to-read compass was the forerunner of the grid compass C-Plath manufactures today.
In 1930, Theodor's son in law, Johannes Boysen, began an apprenticeship to take over the leadership role of C-Plath. Boysen took the company from a specialty craft house to a full-fledged industry, taking the company from 34 employees to 400.
The company, miraculously survived World War I, the World Economic Crisis (the Great Depression in the USA), and even WWII at which time C-Plath provided state-of-the art gyrocompasses and navigation instruments to the III Reich. At the end of WWII, the company almost disappeared when the Allied Forces dismantled the factory due to the prohibition of shipbuilding in Germany. Also, Boysen, the company president, was required to serve a two year prison sentence because he provided equipment to the German military during the war. At this time, the factory was relegated to manufacturing typewriters, spray guns and the works for station clocks of the Hamburg rapid transit system. But with the relaxing of the shipbuilding prohibition in 1949, C-Plath gradually returned to its roots and began manufacturing marine instruments again. By 1953, Boysen had worked out a relationship with Captain Weems to sell C-Plath sextants and compasses in the USA, hence the name Weems & Plath.
C-Plath was operated as a family business for three generations. In 1961, the 100 year reign of a German family-owned business ended when Boysen sold the business to Litton Industries in California. The constant financial need for technological advances in the ever developing marine industry was too much of a strain on the family-owned operation.
C-Plath continued to design and improve navigation instruments for commercial use.
In 1972, the company began to standardize module sizes and developed the new spherical Merkur and Venus compasses that Weems & Plath still distributes today. They also developed a more up-to-date sextant, the Navistar Professional, which had fewer than half of the 150 parts of the Classic sextant. Weems & Plath continued to distribute
C-Plath sextants until the year 2000 when the market for sextants had diminished so much that the company decided to stop production of these world-renowned instruments. Still today after more than 165 years in business, C-Plath is in Hamburg manufacturing the world's finest magnetic compasses and other marine electronic navigation instruments.
