Quote of the Day
People who claim that they're evil are usually no worse than the rest of us... It's people who claim that they're good, or any way better than the rest of us, that you have to be wary of.
— Gregory Maguire
Figure 1: Lignum Vitae tree is a Caribbean
species that is now endangered.
I enjoy woodworking very much and I am now in the process of making a solid walnut countertop by gluing small walnut pieces together. While choosing the wood species for my countertop, I did consider a number of tropical species like teak and ipe. During this search, I heard a person mention that Lignum Vitae was the world's densest wood and is known for being so oily as to be considered self-lubricating. It is also a rare and potentially endangered species.
As I heard this person speak, I recalled that reading years ago that John Harrison had made some of his marvelous wood clocks using Lignum Vitae for its self-lubricating properties. Here is a quote from the Wikipedia on the topic.
Master clockmaker John Harrison used lignum vitae in the bearings and gears of his pendulum clocks and his first three marine chronometers (all of which were large clocks rather than watches), since the wood is self-lubricating. The use of lignum vitae eliminates the need for horological lubricating oil; 18th-century horological oil would get gummy and reduce the accuracy of a timepiece under unfavourable conditions (including those that prevail at sea).
Here are two excellent videos on how Harrison built his excellent wooden clocks.
What really surprised me was that Lignum Vitae was used as a bearing material for submarines as late at the USS Nautilus.
Here are a some photos of ship's bearing (Figure 3 and 4) made using Lignum Vitae.
Figure 2: Propeller Shaft Bearing (source).
Figure 3: More Bearings (source).
read the book ''longitude'' by dova sobel about john Harrison,a british clockmaker,who solved the ''longitude prize'' by making a clock that was taken aboard ships to achieve navigation by being able to tell longitude.