CHAPTER XVII.
THE CLIMATE OF THE SOLOMON ISLANDS.
Amongst the matters to which I devoted some attention in this group of islands, was the annual rainfall. As far as I know, there have been no continuous observations previously made there; and the only record of rain-measurement, which I have been able to find referring to this region, was an observation made on board the Austrian frigate “Novara” in the middle of October, 1858, whilst to the northward of St. Christoval, when three inches of rain were registered in five hours.[491] I therefore set myself to work to do what I could in this matter, making rain-gauge stations at Santa Anna and Ugi and keeping a register myself on board. Mr. Fred Howard undertook to make these observations at Ugi, and I supplied him with a rain-gauge for this purpose. His register, which extended over a period of fifteen months from October, 1882, to the end of the following year, was kept with great regularity; and as I was able to compare his observations with my own on board for a few days, I have every confidence in the accuracy of his observations. At Santa Anna, Mr. William Henghan, to whom I had supplied a gauge, undertook at first to keep the record, beginning in the last week of October, 1882; but he left the island two months after, when Mr. Charles Sproul voluntarily undertook to measure the rainfall, which he did with great regularity until the end of the following year. I regret to learn that Mr. Sproul has recently died at Sydney. He was one of those men who in a quiet inoffensive way have done much towards preparing the way for future settlers in this group. I have the greatest confidence in his observations, since for a few days at Santa Anna we were able to compare our daily measurements.
[491] Scherzer’s “Voyage of the ‘Novara,’” Eng. edit., 1861.
Before proceeding to consider the results of these rain-measurements, I will endeavour to convey to the mental eye of my readers a general idea of the most striking atmospheric phenomenon in connection with the rainfall of these regions. I refer to the oncoming of the black squall.
A clear and serene sky at first gives no token of the sudden change that is to quickly follow; but the stillness of the air and its increased dryness, together with the consequent greater scorching power of the sun’s rays and the apparent nearness of surrounding shores, give sufficient warning of the onset of the rain squall to those acquainted with these seas. In a short time a low black arch appears above the horizon, often in an unexpected quarter, and rising rapidly it sweeps majestically with great swiftness until it appears to span the heavens. Onward it rushes, quicker far than one imagines; and now must the navigator beware. Under yonder advancing arch a white line of foam marks its van. There, away towards one of its corners, a waterspout rises in fantastic shape; sea and cloud meet in mid-air and become intermingled in the whirling column. Lightning plays about beneath the arch and within its black mass, illuming for the moment its dark recesses and leaving it in the next far blacker than before. Peals of thunder herald on the advance of the black squall.
“Clear lower deck!” “Hands aloft!” “Shorten sail!” Such were the words of command which were almost daily issued during our cruises in these islands. In a few brief minutes, the ship is prepared to meet the squall. The temperature falls very perceptibly, and the officer of the watch gives a slight shiver as he dons his oilskins. The wind is freshening, a few large drops of rain fall, the men crouch under the bulwarks, and now the arch is overhead and we are in the thick of the squall. Down comes a deluge of rain which in less than a minute wets all who are unprotected through and through. The ship heels well over, even with her scanty canvas. There is nothing more to be done. We listen to the whistling of the wind in the rigging and patiently wait until the weather clears. In half-an-hour the arch has swept over us, and is pursuing its rapid course towards the neighbouring mountain-peaks, perhaps of Bougainville or it may be of Guadalcanar. The blue sky begins to show itself; and in less than an hour all is as before. With reefs shaken out and more sail made, the ship proceeds, plunging cheerily on under a fresh breeze as though glad to shake herself clear of the squall. The sea losing its murky colour reflects the bright hue of the sky now serene; and its white-topped waves sparkle in the sun. The wizard of the storm has shaken his wand, and the scene is changed, as though by magic.
All nature seems invigorated by this short battle of the elements and to be indebted to the bounty of the black squall. Whilst everything before was depressed and lowering, all is now bright and cheerful. Nature has in truth had its accustomed shower-bath, and the reaction that ensues does good to all; makes men the happier and the stronger, elicits a loud chorus from the lower creation in which bird, reptile, and insect, before hushed in the depressing gloom, now combine in strange medley; and the inanimate world shares in the bright change which has followed the storm.
If it be night, the increased luminosity of the sea may be the warning of the arched squall. The ship throws off a bright wave of phosphorescence on either side of the bow, and leaves a luminous track in her wake. Overhead the cloudless star-lit sky conveys its warning; for the stars shine with increased brilliancy, those of less magnitude usually invisible with the naked eye are now distinctly seen; and if the navigator, who has often tried in vain to count the six stars in the Pleiades, can do so now, let him look out for the black squall. Such are the warnings. Then sweeps along the lowering arched mass with its rain and its waterspouts, its wind and its thunder and lightning. On it comes, looking all the blacker as it spreads athwart the heavens and turns the star-lit night into a lightless gloom. Overtaken in the night by such a squall, unable to see more than half a cable’s length on either side, and perhaps in the vicinity of sunken reefs the position of which is uncertain, a sailor has need of all his wits. On one occasion, when in this situation, we came unexpectedly in soundings, whilst, as we thought, a hundred good fathoms and more lay beneath our keel. The time was anxious, but nothing could be done until the squall was over. When the arch has passed, the stars begin to show themselves, and in a short time they shine out with all their lustre.