May 25, 1882] 



NATURE 



33 



in Egypt has been extraordinary. There has been much 

 rain and very little khamseen, and now there is a brisk 

 north wind blowing, which generally follows the dust 

 wind. Hence many weather-wise people say that the 

 khamseen is over ; if so, of course, all the better. On 

 the other hand, to-night from our sandbank we have wit- 

 nessed a sunset rendered transcendentally beautiful by 

 clouds over fully one half of the sky. It is possible 

 therefore that if the present weather continues, the sky- 

 will not be quite so free from vapour as it is generally in 

 Upper Egypt. To avoid the khamseen, General Stone, 

 who has had the region reconnoitred, has suggested to 

 the English party to occupy an eminence to the north- 

 west of Akmin, a village a little higher up the river than 

 Sohag. 



Near Soling. Sunday 



I had got so far at 1 1 last night, when the time came 

 for closing the mail bag, although we were fast aground, 

 and apparently with less chance than ever of getting off. 

 There were two mail bags, however, made up after all, 

 for the service is so interfered with higher up the Nile 

 that I am still in time on Sunday evening to send a letter 

 which ought to catch the next Brindisi mail, though 

 whether it does or nor is very doubtful, for we have been 

 aground again twice to-day. 



So, as we have at last arrived at our station, I will 

 endeavour to give an idea of" the proposed arrangements. 

 In the first place, we have found the steamer on which 

 ous parties are to live as the guests of the Khedive 

 moored close to the shore, at a point where it trends north 

 and south, or very nearly so, about half a mile below 

 Sohag. This position, which has been selected by the 

 French party— the first to arrive— is a very admirable one 

 for two reasons. First, the constant wind during the last 

 week has been from the north, and by keeping a staff of 

 people watering the foreshore of the Nile, all dust rs ob- 

 viated. To the north of the place of observation trees, 

 and what looks like grass from a distance, grow close to ' 

 the margin of the river ; so that the dust can only be of 

 nearly local origin ; while a long stretch of sandbank to 

 the north, running east and west, is far enough away to 

 deposit its sand in the Nile before it can reach us. 



Secondly, the khamseen, if khamseen there is to be, 

 will have to travel a mile and a half along the Nile before 

 it can enter the observatories ; and it is thought this 

 amount of water surface will have an important effect in 

 reducing the amount of sand in the air, even in us case 

 also. Nous verrons. These considerations have induced 

 the English party to take up ground close to the boat and 

 their French confreres. The hills which look so tempting 

 in the mass are simply impossible as places of observa- 

 tion. With the means at command here it would take a 

 week to get the instruments up, much more in position; 

 while at Akm'an, which is only two or three mile , away, 

 there does not seem to be any spot more f.i- 

 takiny everything into consideration, than the one here. 



At five o'clock to- mono. v, then, the work will begin, 

 and the next week will be a busy one, for in spite of the 

 fresh breeze and the clouds— for there are very distinct 

 clouds to-day- -work on the sand becomes very oppressive 

 in the middle of the day, and there are heavy weights to 

 move, which the observers must move themselves. The 

 scene from the ship is already interesting. To the north 

 two tents and various shelters, to the south one tent. 

 These will increa : e to six to-morrow. Here and there 

 groups, looking down the bank, stealthily from between 

 the trees. There is a pretty thick grove of acacia trees, 

 which shelter us somewhat from the rays of the setting 

 sun, still fierce in this latitude. Here and there, skirting 

 the grove, a sentinel with fixed bayonet keeping guard. 

 At the extreme south, tents for the military, and a long 

 line of piled arms. 



Acro.-s the water the scene is novel and beautiful in the 

 extreme. The main Nile, in which the bat is anchored, 



is here about half a mile wide, but there is an island 

 about two miles long, and a wide stretch of water beyond 

 that. This island forms, with the river, the foreground 

 of the landscape. With an opera-glass we can see the 

 Fellaheen cultivating the ground almost to the water's 

 edge in places, and looking after their crops of maize or 

 their flocks of goats. Here cones a veiled Rachel to the 

 sacred river to fetch water for a house in an indistinct 

 flat-topped village, sheltered in a large group of beautiful 

 palm trees. The arm of the river beyond the island we 

 cannot see, but a background is not lacking. A long line 

 of mountains, we may almost call them, full of geological 

 tracery, are now, as I write, almost blood-red in the light 

 of the setting sun, and are surmounted by that grey 

 purple one always sees to su.h advantage in Eastern 

 lands — both grey and purple haze in a few hours to give 

 way to the silver dawning of the moon, now terribly 

 dwindling in her visible surface, and reminding the 

 astronomers of the coming seventy seconds in a most 

 forcible manner. 



The proceedings at the end of the first day on which 

 the English and French parties found themsehes together 

 as guests of the Egyptian Government natural!) inclu led 

 some toasts — that of his Highness the Khedive, proposed 

 by M. Tre'pied, and that of the English and French 

 nations, proposed by Moktah Bey, and responded to by 

 Mr. Norman Lockyer. The arrangements on b >ard are 

 as perfect as those made at the various stations on shore, 

 and one's national pride is a little touched at the idea 

 of what the Government reception would be of a party of 

 Egyptian astronomers coming to England to observe an 

 eclip e of the sun. 



ANEMOMETRICAb OBSERVATIONS OX 



BOARD SHIP' 



IT is kno.tn that the determination of the velocity of the 

 wind in the o^ean has always bee-n one of the 

 desiderata of meteorological observations. Maury devoted 

 much attention to this subject, and to determine, at least 

 approximately, the velocity of trade-winds, lie was com- 

 pelled to work o'.i a very unsafe basis — the velocity of 

 ships during different parts of the year — and to put aside 

 all observations made in accordance with the seale ot 

 Beaufort as unreliable. But it is obvious that the velocity 

 of a ship depends on so many circumstances quite inde- 

 pendent of the wind itself (such as the shape of the ship, 

 the surface of its sails, the disposal of the cargo, and so 

 on), that its velocity is tut a very imperfect means of 

 measuring the velocity of wind. Besides, the relation 

 which easts between the force of the wind and the 

 velocity or a ship, under different angles between the 

 direction of both, is a new source of error, as this relation 

 has not >et been established with accuracy, and can be 

 established only by means of anemometric measurements. 

 The necessity of trustworthy measurements of the velocity 

 of wind at sea was so well understood in England that 

 the Royal Society and the British Association esl 

 in 1859 two anemometers — one on the Bermuda Islands, 

 and the other at Halifax. But it is known th,.t the force 

 of the wind is usually lessened on continents an 1 islands. 



Therefore it was absolutely necessary to ma! c auemo- 

 metrical observations on board ships, and a lew attempts 

 had already been made in this direction. Prof. Piazzi 

 Smith invented an anemometer which might be esta- 

 blished on board a ship, and which merited the highest 

 eulogy from Maury, but Lieut. Domojirov does not know 

 if any observations were made with it. Emil Bessel, 

 during the Arctic expedition of the Polaris, made a series 

 of observations with an anemometer on board his ship, 

 but he does not explain, neither the methods of observation, 

 nor the corrections he applied to his measurements. In 



1 A Domojirov, in the [zvestia of .the Russian Geographical Society, 



