Abstract: A self leveling adapted to be moved along a substantially vertical wall comprises a base assembly adapted to be moved up and down along the substantially vertical wall, a roller assembly pivotally connected to the base assembly to be in continuous contact with the vertical wall, and weight means pivotally connected to the roller assembly. The leveling device is further provided with a horizontal member connected to the weight means perpendicular to an imaginary vertical line extending through the weight means.

Abstract: A liquid sampling device comprises a length of pipe having a cap screwed onto each end thereof. The device is provided with means for suspending it with the axis of the pipe oriented vertically. The upper cap has an aperture for admitting the liquid to be sampled. The lower cap has an aperture and a stopcock which may be opened to permit the sampled liquid to flow out of the device for inspecting and testing. The flow resistance of the aperture, generally determined by the diameter thereof, and the volumetric capacity of the device relative to the viscosity of the liquid and the depth of a body thereof to be sampled will be selected so that when the device is lowered to the bottom of the body of liquid and then lifted out therefrom, the device will not fill to capacity, whereby a representative sampling is assured throughout the depth of the body of liquid.