November 14, 1890.] 



SCIENCE. 



275 



frtoi-m ceased suddenly. " Why,'" said the •' Listener" to himself, 

 " that was like the sudden ceasing of a hail-storm." A queer 

 thought about the dieatn came t'§ him. He lighted a lamp, and 

 looked out iipon the roof of the porch, and there were many little 

 heaps of fast-melting hailstones. Now, had the pelting of the 

 hail upon the roof suggested that dream -presentation of tlie per- 

 sonality of Mr. Hale f Very likely it had. But by what process 

 •of consciousness? Evidently the dreaming consciousness or per- 

 ception was superior to the waking consciousness ; for, it the storm 

 ■suggested the dream at all, the dreamer must have been aware 

 that it was hail that was falling, in order that Mr Hale should 

 come forth; but, when he really woke froni sleep into full con- 

 sciousness, he took the storm for rain, and there was no thought 

 of hail in his mind. It is a nut for the psychologists to crack, if 

 they think it worth their while. 



— During the month of .August last, the Mediterranean fleet of 

 the French Navy was supplied with a captive balloon for the pur- 

 pose of reconnoitring. The balloon, according to Engineering of 

 Oct. 34, was constructed at the military balloon works at Calais 

 Meudon, and has a capacity of 11,300 cubic feet. It is inflated 

 with hydrogen, which is carried in reservoirs under a pressure of 

 100 atmospheres. A tail-rope 130 feet long, which for lightness is 

 best made of silk, serves to connect the balloon with a ship of the 

 fleet. A number of ascents have been made with the balloon 

 from the armor-clad " Formidable," the tail-rope being connected 

 to the top of one of the military masts. Many officers of the ves- 

 sel have made ascents, and are unanirnous in their praise of the 

 apparatus. On a clear day all important objects within a radius 

 of eighteen to twenty four miles can be clearly distinguished. 

 Another important point is that the waters of the sea, when ob- 

 served from a considerable altitude, are singularly clear, and the 

 details of the bottom were in some of the ascents clearly distin- 

 guishable, even at depths of SO feet. This peculial-ity allowed an 

 observer in the balloon to follow the movements of the sub:narine 

 boat "Gymnote," during its recent trials, without losing sight of 

 it for a single instant, whatever its depth of immersion. The 

 balloons used are very stoutly constructed, and in September last 

 one was towed at a speed of 10-| knots per hour for a distance of 

 21 knots by the torpedo-boat " Audacieux" without suffering the 

 slightest damage. It may be remarked, in conclusion, that Ger- 

 many has also adopted balloons for naval purposes, and, during 

 the recent manoeuvres at Wilhelmshaven, one of these was used 

 from the war-ship "Mars '" for reconnoitring. 



— The first determination of the moon's mass was made by 

 Newton in 1687, from the tides, and other investigators have since 

 employed the same method, but for more than one hundred and 

 eighty years it yielded no trustworthy result. Its failure was due 

 to various causes, both theoretical and practical; and, although 

 some of these were cleared up by La Place as early as 1818, there 

 was little prospect of success until the recent application of har- 

 monic analysis to the reduction of continuous observations of the 

 tides, recorded by automatic gauges, and extending over long 

 periods of time. Long ago Airy showed why the moon's mass 

 cannot be accurately determined from the mere ratio of the solar 

 and lunar effects in the semi mensual inequality of the tides; but 

 nevertheless many of the values recorded have been obtained in 

 that very way, and are therefore worthless. Those found by La- 

 Place's method, or by Ferrel's modification of it, are theoretically 

 ■correct, at least for deep-water tides; but, instead of confining 

 himself to them, Professor William Harkness of the Naval Obser- 

 vatory, Washington, has computed many new values from the 

 ■" Results of the Harmonic Analysis of Tidal Observations," which 

 have been published by Major Baird and Professor Darwin. The 

 final result of Professor Harkness's work is — 



Mass of Moon = 0.012714 ± 0.000323. 



— A memorandum, together with a sample of the plant, lately 

 received from Sir Alfred Moloney, the Governor of Lagos, says the 

 Journal of the Society of Arts (London) of Oct. 24, gives an ac- 

 count of the endeavor he is making to encourage the exportation 

 of the fibre known as " African bass," — the fibre of the bamboo- 

 palm (or Raphia vinifera). The bamboo-palm {Raphia vinifera) 

 is perhaps the commonest tree in the swamps and lowlands which 



line the waterways of the colony. Dense thickets of these palms, 

 traversed only by the palm wine-gatherer or the bamboo-cutter, 

 push their way into the lagoons, and extend over the flood 

 grounds, and even to a distance of from fifteen to twenty miles 

 up the river-valleys into the interior. The area occupied by these 

 Raphia forests it would be impossible to calculate ; but it may be 

 accepted without doubt that they extend throughout the length 

 of the colony, and to a distance of at least fifteen miles from the 

 seacoast, and that over this area of about five thousand square 

 miles they form a considerable proportion of the vegetation, next 

 only in numbers to the oil-palm (Elaeis guineensis) and the man- 

 grove {Rhizophora mucronata). The fibre itself is the one in most 

 common employment on the coast, being used by the natives for 

 all sorts of purposes, — cloth, cordage, thatch, fishing-lines, etc. 

 The cost is only that of collection and preparation, the latter being 

 a very simple process of soaking and scraping. The price, deliv- 

 ered in England, is said to be from ll.'iO to $160 per ton for good 

 fibre. The cost of production is estimated at |70 per ton; ship- 

 ping and other expenses, at $3^.50. 



— Some time since, Mr. Albert Koebele, the California agent of 

 the Division of Entomology of the United States Agricultural 

 Department, was instructed to collect and forward to Mr. Wight 

 in New Zealand a number of living specimens of a common 

 Raphidia which he had found to destroy the larva and pupa of 

 the codling-moth in California. This was done as a partial return 

 for Mr. Wight's kindness to Mr. Koebele when he was in New 

 Zealand in the spring of 1889, collecting the insect enemies of the 

 fluted scale. Recent letters from Mr. Wight, and an article in 

 the June number of the New Zealand Farmer, state that the ship- 

 ment arrived in fairly good condition, although it was opened for 

 examination, and held for ten days, at the custom-house. Twenty- 

 one specimens were sent, each one in a small box with moss, and 

 the whole enclosed in a strong wooden box. Mr. Wight found 

 pupse in sixteen of the boxes, and a larva in one; while three were 

 empty, probably owing to the custom house examination. The 

 single larva was hungry and very attenuated, and it at once 

 attacked and devoured a codling-moth larva twice its own size. 

 It was so stretched out and distended that at first, not discovermg 

 the absence of the codling moth larva, Mr. Wight thought it was 

 entering the pupa stale; but it presently resumed its usual appear- 

 ance, and finished several more larvae. The result of this importa- 

 tion is looked forward to with great interest. The genus Raphidia 

 is i-epresented in this country only upon the Pacific coast, and it 

 is not at all likely that it will flourish East. An attempt, how- 

 ever, will be made to introduce this ravenous creature into some 

 of our Eastern apple-orchards. 



— Next to the cabbage-worm, the worst insect enemy of the 

 cabbage is the aphis, or plant-louse, which is so often found upon 

 the leaves and in the heads in great numbers. This is a small, 

 bluish-white insect, that subsists upon the sap of the plant, and 

 multiplies with great rapidity. Like mosti of the peculiar family 

 to which it belongs, this insect has the power, not common among 

 insects, of bringing forth living young; but with most of those 

 that have been carefully studied there is in the fall a sexual gen- 

 eration by which the true eggs are laid, and in this egg state most 

 of them pass the winter. But although the cabbage aphis has 

 been known both in Europe and America for more than a century, 

 the sexual generation has never heretofore been found, and en- 

 tomologists did not know where or when the eggs were laid, nor 

 how the insect passed the winter. Recent investigations, how- 

 ever, carried on at the Ohio Experiment Station by Dr. 0. M. 

 Werd, have shown conclusively that the sexual generation develops 

 late in autumn on the cabbage, and that the eggs are laid on the 

 cabbage-leaves. The true male is a small winged creature, with 

 a moi-e slender body than the other winged forms. The egg-lay- 

 ing female has no wings, and is pale green in color. This discov- 

 ery of the fact that the insect passes the winter in the egg state 

 on the cabbage-leaves has an important economic bearing. It 

 suggests, as one of the best ways of preventing the injuries of this 

 pest, the destruction during winter of the old cabbage-leaves 

 with the eggs upon them, instead of leaving them undisturbed 

 until spring, as is too often done. 



