Inventor David M. Weston

In 1851, two years after Honolulu businessman Henry A. Peirce and partners William L. Lee and Charles R. Bishop founded Lihu‘e Plantation with $16,000 in capital, Peirce was in Boston, Mass. to conduct business that included the purchase and shipment of Lihu‘e Plantation’s milling machinery to Kauai.

While in Boston, he also convinced an ingenious expert machinist named David M. Weston (1819-1890) to accompany the shipment and assemble and erect the Lihue mill.

When Weston’s job at Lihu‘e Plantation mill was finished, he joined East Maui Plantation where, later in 1851, he invented a centrifugal machine that quickly separated molasses from sugar during the milling process.

Weston’s machine, named the “Centrifugal Separator,” was basically a perforated cask into which a mixture of sugar and molasses was thrown and spun very fast.  While spinning, molasses was forced out of the cask through the perforations, leaving only sugar.  

Centrifugal separators revolutionized sugar manufacturing in Hawai‘i by reducing the time needed to separate sugar from molasses from weeks to minutes, while at the same time producing a superior sugar that could be sold at much higher prices.

A year later, Weston, with financial backing from Peirce, established Honolulu Iron Works, a machine shop and foundry that produced the equipment, tools and machine components of sugar mills for many years, including the centrifugal separators Lihu‘e Plantation used in milling its first sugarcane crop in 1853.  

During that first harvest, teams of oxen hauled harvested sugarcane in wooden carts to the mill Weston had built.  There, granite rollers made in China ground the sugarcane to extract its juice, which was then cleaned and boiled at precise temperatures to produce a mixture of sugar and molasses that was then spun in Weston’s centrifugals to separate sugar ready for shipment in wooden kegs to Honolulu.