On 4/24/2010 12:46 PM, CWLee wrote:

As the OP, it appears to me that "Bob Villa" had the best answer. His
link to a "6-Inch Hand Held Optical Level" brought up a photo of a
device pretty much the same as what I have. That link was to Amazon, and
the particular brand shown there is priced at about $40. Another link
took me to a similar version by Stanley at about half the price.

Now I know what it is called. Any other information about common
applications and uses would be appreciated.

Thanks everyone.

The application would be to find a rough estimation of the elevation
of two objects relative to your line of sight, or to set a rough
elevation (say along a wall) relative to your line of sight. The
device works similar to a surveyor's elevation transit, without
the bells and whistles, and is as accurate as the talent of the
user.

Generally the instrument requires two people. One to look through
the device and one to hold a measuring stick of some sort. If
used for gauging elevations you only need yourself if there is
not a need for measuring an actual elevation i.e. look at something
with the bubble at level and note its position (above/below) the
horizontal line in the scope, then look at something else, without
moving your position, with the bubble at level and note the difference
in elevation from the first item you looked at.