Many runways lack an ILS/GS but have DME on the centre line (e.g. Lagos R/W 19) and DME can provide information in conjunction with the pressure altimeter to define a glide slope. For Lagos R/W 19 I have developed a method of calculation and have tried out the resulting table on two occasions. The pilot not flying the plane consults Table 1 and calls out deviations above or below the glide path (which meets the sloping runway 1500 ft from the threshold for a DC-10).