“Beveled end caps! Boy do we totally understand the question. The size and shape of the end caps are the way they are for two reason. First, the material is different and can expand and contract at different rates. We can’t allow any chance that an end cap might ever be larger because that would throw off the accuracy of the level! And the second reason the end caps have beveled edges is to avoid sharp corners.

Sensitivity! What a great question. That’s at the heart of any highly accurate measuring system. Sensitivity varies with and is almost a function of vial shape, material, texture and size. We use a barrel-shaped vial and a specific texture in order to control the speed of the bubble traveling through the vial; we balance those features while maintaining the highest possible accuracy which is comfortable to use for tradesmen. It is possible to be even more accurate, but then the level becomes finicky and difficult to use.

Bubble size. It is not a good thing to have a larger bubble that gets closer to the lines for the very reason you mentioned! In cold temperatures, the bubble gets larger. If the bubble gets so large that it touches both lines, the level is useless.”

I hope Jason’s explanations help!
Gary

This snippit of the past gives me pause to think that dispite the newfangled materials and tools we have at hand, the heart and soul of carpenters / builders hasn’t changed in all the years. It’s neat to think that someday – a hundred years from now – someone like Jeff will bring something written in our time about construction to our “Brother Builders” attentiion in that time.