B67-575 INCLINOMETER. Nilson Patent. Patented in 1900 by Magnus Nilson of Oakland, CA, this level features two side-by-side level vials, one of which is mounted on a rotating brass plate. The patent shows the vials being independently rotated, and the plumb vial also being adjustable, but in every one of the very few known examples the second vial and the plumb vial are fixed. It also features a sighting tube through the stock. 28" long, good vials, brass tipped, mahogany stock has some dings including a 1-1/2" dent but no real damage. Good clean example of a very rare patented inclinometer. From the collection of Jim Gehring. Good+ 300-600