A folding sighting device to define and then to relocate the point where the user is placed, said device allowing the user to simultaneously identify linearly opposite reference points to establish a first reference line, and to subsequently fix and record linearly opposite reference points to establish a second reference line which intersects the first reference line. The sighting device or site relocator has an elongated base member with coordinating sighting elements at the opposite ends so t...

A method of and apparatus for the installation and retrieval of instrumentation hardware supported through a hole in a section of ice is provided wherein an expansion member such as an inflatable bladder is utilized for displacing water normally subject to freezing within the hole. The inflatable bladder comprises an elongated expandable sleeve of sufficient length to substantially extend the ultimate depth of the hole in the ice for engaging and bearing against the sidewalls thereof. A portion ...

A mile post and mileage indicator for maintaining the exact mile post position of a vehicle while said vehicle is travelling upon a roadway containing designated mile post signs, which increase or decrease in a particular direction. This indicator may also be used to indicate exactly how far the vehicle has travelled or how much further it must travel before it reaches a certain destination. The indicator contains a plurality of dials, each dial having two columns of numbers. One column is numbe...

A capillary depth gauge employs a transparent cover member having an annular magnifying lens portion overlying the capillary passageway to facilitate reading of the gauge.

A digital auto focus system includes first and second detector arrays which receive first and second detection images of an object. The detection images are displaced by a number n of detectors depending upon the distance between the object and the detector arrays. The output signals of the detector arrays are processed to provide a signal indicative of the number n. This signal may be used, for example, to control the position of a lens in a photographic system.

A portable navigational instrument has edge portions which are adjusted so that the instrument's orientation with respect to a vessel can be maintained constant in different positions within the vessel's wheelhouse. Bearings of objects are determined by a sighting arrangement which co-operates with a scale which is set in accordance with the vessel's steering compass bearing, corrected for deviation, whereby the need for a compass on the instrument is avoided. The sighting arrangement can compri...

An ellipticity control system for controlling the elliptical deviation of the vibratory element of a displacement sensor. The apparatus incorporates a plurality of drive electrodes, at least six in number, mounted concentrically along the longitudinal axis of the elongated vibratory element. Each drive electrode is formed in pairs oriented along separate axes. A pair of X-axis pickoffs and a pair of Y-axis pickoffs axially spaced from the drive electrodes are also mounted concentrically of the v...

A wave measuring buoy for measuring ocean surface wave amplitude and frequency is disclosed. The buoy includes a single-axis accelerometer suspended as a pendulum inside a water-proof housing. The waterproof housing is connected to and beneath the flotation hull of the buoy and is located at the center of rotation of the buoy assembly so that the accelerometer is substantially insensitive to roll and pitch motions of the buoy. The output of the accelerometer is an analog signal proportional to t...

A device to be used by brickmasons in the erection of a brick wall that embodies, speed in setting-up, precision and choice of mortar joint spacing and is adjustable to a variety of wall heights.

A distance measuring device for attachment to the hub of a vehicle wheel includes a pendulum, which remains generally stationary, as the hub rotates. A counting mechanism rotates with the hub, and is coupled through a worm wheel and lost-motion mechanism to the pendulum. The lost-motion mechanism reciprocates a feeding arm against the bias of a spring, which shifts periodically back and forth over center, as the lost-motion mechanism periodically transmits motion. A feed spring, mounted on the f...