B65-572 GRAVITY INCLINOMETER. Deck Patent. The inclinometers patented by Thomas Deck of Toledo and manufactured by Deck's Gravity Level Co. have an unusually elaborate balancing mechanism to support the needle that tends to make it very sensitive but not very practical. This is the 30" version, cherry stock has some minor scratching, brass dial has some oxidation but no damage, needle moves smoothly. A very uncommon and collectible level. From the collection of David Jeffers. Good+ 200-400