There was no sound now in the observatory, and the lantern waned steadily.  Outside there was the occasional cry of some animal in alarm or pain, or calling to its mate, and the intermittent sounds of the Malay and Dyak servants.  Presently one of the men began a queer chanting song, in which the others joined at intervals.  After this it would seem that they turned in for the night, for no further sound came from their direction, and the whispering stillness became more and more profound.

The clockwork ticked steadily.  The shrill hum of a mosquito explored the place and grew shriller in indignation at Woodhouse’s ointment.  Then the lantern went out and all the observatory was black.

Woodhouse shifted his position presently, when the slow movement of the telescope had carried it beyond the limits of his comfort.

He was watching a little group of stars in the Milky Way, in one of which his chief had seen or fancied a remarkable colour variability.  It was not a part of the regular work for which the establishment existed, and for that reason perhaps Woodhouse was deeply interested.  He must have forgotten things terrestrial.  All his attention was concentrated upon the great blue circle of the telescope field—­a circle powdered, so it seemed, with an innumerable multitude of stars, and all luminous against the blackness of its setting.  As he watched he seemed to himself to become incorporeal, as if he too were floating in the ether of space.  Infinitely remote was the faint red spot he was observing.

Suddenly the stars were blotted out.  A flash of blackness passed, and they were visible again.

“Queer,” said Woodhouse.  “Must have been a bird.”

The thing happened again, and immediately after the great tube shivered as though it had been struck.  Then the dome of the observatory resounded with a series of thundering blows.  The stars seemed to sweep aside as the telescope—­which had been undamped—­swung round and away from the slit in the roof.

“Great Scott!” cried Woodhouse.  “What’s this?”

Some huge vague black shape, with a flapping something like a wing, seemed to be struggling in the aperture of the roof.  In another moment the slit was clear again, and the luminous haze of the Milky Way shone warm and bright.

The interior of the roof was perfectly black, and only a scraping sound marked the whereabouts of the unknown creature.

Woodhouse had scrambled from the seat to his feet.  He was trembling violently and in a perspiration with the suddenness of the occurrence.  Was the thing, whatever it was, inside or out?  It was big, whatever else it might be.  Something shot across the skylight, and the telescope swayed.  He started violently and put his arm up.  It was in the observatory, then, with him.  It was clinging to the roof, apparently.  What the devil was it?  Could it see him?

He stood for perhaps a minute in a state of stupefaction.  The beast, whatever it was, clawed at the interior of the dome, and then something flapped almost into his face, and he saw the momentary gleam of starlight on a skin like oiled leather.  His water-bottle was knocked off his little table with a smash.