Shapley Constellation III in the Large Magellanic Cloud (LMC) is surrounded by a ring of HII regions, called Supershell LMC 4 (Meaburn 1980). In the direction of the centre of this spatial strucutre very little neutral interstellar gas is found (McGee & Milton 1964). The spatial arrangement suggests that a hole exists in the gas layer of the LMC, one which may be blown out by the effect of the winds of the stars of Constellation III or by supernova blasts from the same area. Shock waves moving into surrounding neutral gas triggered star formation in the outer shell. Left inside would be a volume of diluted, and probably hot, ionized gas.
To probe the spatial structure of the gas we have collected high dispersion IUE spectra of some stars inside LMC 4. We have analysed the interstellar lines from the various elements and ions available and are able to derive the velocity structure of the lines of sight observed (Bomans & de Boer 1989). We see a well-defined absorption component near 230 km s−1 and a broader structure around 280 km s−1. The column density of neutral gas is small, as confirmed from the HI 21-cm profiles of Rohlfs et al. (1984). We have redetermined the spectral type of the stars from the IUE spectra in order to estimate the strength of the stellar Lyman-Alpha (Lα) line. Two stars are of early enough type to allow the determination of N(H) from Lα.