A prototyping glass RPC with excellent signal to noise ratio was constructed and tested.Detection efficiencies for cosmic rays of about 95% were obtained for both avalanche and streamer modes of operation.A simple method to measure the signal charge profile is developed which consists with other methods such as direct optical observation.A narrow profile for avalanche signal mode is obtained which may lead to an intrinsic spatial resolution of smaller than 0.4 mm in FWHM.If delay-line or charge division technique is used to determine the centrode of the signal charge distribution, it is important to reduce fluctuations of the delay-line (or resistor) units in order to reach the ultimate intrinsic position resolution.