'i6b 



NA TURE 



[December 5, 1907 



that Prof. Campbell's party is equipped with a fine 

 set of instruments, and that it is prepared to cover 

 a wide field of research. 



Although the above will be the only official expedi- 

 tion to the island, an enthusiastic amateur in the 

 person of Mr. F. K. McClean is already wending 

 his way there. Mr. McClean is the son of the late 

 Mr. Frank McClean, F.R.S., who, it will be remem- 

 bered, besides completing' a valuable spectroscopic 

 survey of the brighter stars in both hemispheres, made 

 valuable endowments both to the Cape Observatory 

 and the Cambridge University. 



At the eclipse of 1905 Mr. F. K. McClean accom- 

 panied the Solar Physics Observatory's expedition to 

 Majorca as volunteer assistant. On that occasion he 

 was in charge of a large coronagraph of 16 feet focal 

 length, which he manipulated successfully, so he is 

 not a novice at eclipse work. 



For the coming eclipse he is taking out a fine 

 22-inch siderostat, one coronagraph, and a small 

 grating spectrograph. The coronagraph consists of 

 a 4i-inch De la Rue objective of 8 feet focal length, 

 which has been used on numerous occasions during 

 eclipses by the Solar Physics Observatory expeditions. 



The optical parts of the grating spectrograph con- 

 sist of a 4-inch Voigtlander of 42 inches focal length, 

 and a Thorp's transparent replica of a Rowland 

 diffraction grating having 14,500 lines to the inch 

 and a ruled surface of 3 x 2 inches. In the eclipse 

 of 1905 this instrument gave such satisfactory results 

 that l\Ir. McClean wished to employ it again under, 

 it is hoped, better weather conditions. 



Mr. McClean has so arranged his piogramme that, 

 failing anv assistance at the station, he can make 

 exposures in both the instruments. There is little 

 doubt, however, that Prof. Campbell will be able to 

 render him help should he require it. 



It mav be mentioned that if the Annapolis had been 

 able to accommodate more than twelve of the eclipse 

 partv Mr. McClean would have been invited to join 

 the ' Lick expedition. To reach Flint Island he has 

 therefore gone to Auckland vid Australia, and has 

 chartered a special steamer to take him and his 

 equipment to the island and back. From later in- 

 formation I find that, by arrangement with Prof. 

 Campbell, he will pick up at Tahiti Mr. C. J. Mers- 

 field, of the Roval Society of Sydney, and Mr. Moors, 

 of the Svdnev University, both of whom have volun- 

 teered to act as Prof. Campbell's assistants, and will 

 convev them to Flint Island and back to Tahiti. 



Let us hope that eclipse day will be fine, and that 

 all will return with results w-hich will add to our 

 knowledge of the sun. 



A cablegram, dated November 25, from Mr. 

 McClean, at Auckland, states that Mr. Mersfield has 

 joined him and will be attached to the Lick party. 

 He further informs me that Mr. Ravmond, of the 

 Sydney Observatory, and Mr. Short, photographer to 

 that observatory, together with the Rev. Mr. Walker, 

 an amateur astronomer at Auckland, are going out 

 with him and will form his party. 



William J. S. Lockyer. 



NEW AEROPLANES. 

 A N account of the successful aeroplane flights bv 

 -'*- which Mr. Henry Farman has succeeded in 

 breaking the record hitherto held by M. Santos 

 Dumont (in the absence of trustworthy information 

 concerning the experiments of the Wright brothers) 

 has probably been seen by most readers of Nature 

 in the daily papers. We are indebted to an article 

 by M. Rene Doncifere in La Nature for the further 

 NO. 1988, VOL. ^y] 



details regarding the machine and its performances 

 which form the subject of the present notice. 



Mr. Farman's machine has been constructed in the 

 works of Messrs. Voisin Brothers, and is of the well- 

 known cellular form, as shown in the accompanying 

 illustration. The front pair of planes measure 12 x 2 

 metres, the height between them being 2 metres. 

 This pair is connected by a framework 43 metres long 

 with the rear pair of planes, which only measures 

 6 metres transversely. The vertical rudder is situated 

 between the latter planes, while a horizontal rudder 

 is fixed right in front of the machine. The motors 

 and tanks of petrol are contained in a spindle-shaped 

 case in front, into which is let the seat for the 

 operator. 



The motive power is furnislied by an eight-cylinder 

 " Antoinette " motor of 40-50 (metric) horse-power, 

 and operates on a propeller the two vanes of which 

 are 2' 10 metres across and I'lo metres in pitch. The 

 whole apparatus rests on four wheels when on the 

 ground. The total wing surface is 52 square metres 

 and the weight 500 kilograms ; the length of the 

 machine is 10 inetres. At present — or at any rate at 

 the tiine of M. Donciere's account — the machine has 

 a tendency to take an upward direction on leaving the 

 giound, but while this prevented Mr. Farman from 

 making extended trips, lie has nevertheless succeeded 

 in covering 771 to 800 metres at a height of 6 metres 

 above the ground. These records, performed on and 

 after October 26, following after flights of 303 and 

 350 metres, represented the ma.ximum course obtain- 

 able within the limits of the field on which the experi- 

 ments were made. 



In regard to what the average Englishman would 

 call the " practical " aspect of these experiments with 

 reference to the possibilities of aeroplane machines 

 coming into general use, reference is made to the 

 great skill needed in controlling the machine. The 

 operator has to manipulate or observe at the same 

 iTioment the vertical and the horizontal rudder, the 

 carburettor, the sparking, the pressure gauges of the 

 pcttol and water, to listen to the throbbing of the 

 motor, to balance the machine laterallv, taking 

 account of the effects of wind, and finally to avoid 

 coming into collision with the crowd of spectators. 



Later news states that Mr. Farman has again made 

 several attempts to win the Deutsch Archdeacon 

 prize, but has failed to do so owing to the wheels of 

 his machine grazing the ground, especially in the 

 neighbourhood of the turning points. 



.\nolher aeroplane which is also attracting con- 

 siderable attention at Paris is the " monoplane " of 

 M. Robert Esnault Pelterie. This, unlike most recent 

 types, has only a single transverse supporting surface, 

 which in one machine measured q"6 metres from tip 

 to tip with a superficial area of 18 square metres ; in 

 a more recent machine these dimensions have been re- 

 duced to 8'6 metres and 16 square metres respectivelv. 

 The surface is somewhat concave in form. In addition 

 there is a single horizontal rudder placed at the rear, 

 while the motor and propeller are in the front of the 

 machine. The motor consists of seven cylinders 

 arranged round a circle, and it gives 25 to 30 horse- 

 power with a weight of 44 kilograins. The total 

 weight of the machine and its rider amount to 240 

 kilograms. For running along the ground the mono- 

 plane has two wheels, arranged bicycle-fashion, at- 

 tached to the body, and two other wheels are attached 

 to the tips of the wings. The recorded performances, 

 \\hich commenced on October 22, include straight 

 flights of about 100 metres and 147 metres, and a 

 path stated to be a semicircle of radius about 1640 

 feet, which, if correct, represents a flight of, roughlv. 

 1600 metres. But at the end of the flig"ht of 147 



