A Brief Word

| October/November 1996

Kermath marine engine


James Potee

Typically, our inquiries drop off dramatically during July and August. After all, most people are spending their time displaying their restorations of last winter as well as buying new iron for their 1996-97 winter projects. Thus, we've combined a report of our recent British tour, along with a dozen photographs highlighting a few of the interesting sights and sounds.

We saw some ancient crafts revived at Tatton Park and elsewhere. Particularly impressive was the foot-powered 'pole lathe.' A block of wood is split to approximate dimensions and is then cut to length and put in the lathe. The operator wraps a strong cord around the piece, and by pushing down on the foot treadle, it turns between centers. By careful manipulation of the cutting tool, the piece is quickly rounded for about 2/3 of its length, and is then quickly turned end-for-end to rough out the remainder. A strong flexible tree limb serves as a return spring on the pole lathe, so the spindle turns back and forth.

The spindles in genuine Windsor chairs were made in this manner for many years, and even with mechanization of the process, this ancient hand method was still faster than what could be achieved with highly mechanized methods. A good artisan could split out a rough block, put it on centers, cut and finish it, and be ready for another in four minutes or less!

Although much slower than wood, early metal cutting was accomplished in much the same manner. It's always hard to put things in a historical perspective, and it's even more difficult to conceive of the crude methods used by our ancestors as the magnificent machine tool industry was developed. Yet, it all goes back to crude machines like the pole lathe.

The other day we ran across an article in the August 2, 1906 issue of American Machinist outlining the history of Babbitt metal and its inventor, Isaac Babbitt. The latter was born at Taunton, Massachusetts, on July 26, 1799, and died on May 26, 1862. After an apprenticeship in the goldsmith's trade he became quite interested in the production of alloys, and in 1824 he became the first person in the United States to produce brittania metal. Used for various types of cookware, brittania metal consisted of 88.9% tin, 7.4% antimony, and 3.7% copper. Thus, Babbitt's original bearing metal was simply brittania metal. However, little is known of his methods of mixing the metals to form the alloy, and therein was the secret to Babbitt's success.

Regarding the mixing of metals to form the alloy, it has been determined that Babbitt developed a specific order during the process, adding a portion of one metal, then another, and so on, until the full quantity of each had been added to the kettle.