CHAPTER XXI

JOURNEY’S END

SLEEP came slowly to me that first night at Furawia. I was excited

as I had not been since saying good-by to Lieutenant Bather at Sollum

and beginning the journey. Now I was in touch again with the outside

world and the journey was really over, even though it would still be a

month or more before I should exchange my caravan for other methods of

travel. The “lost” oases of Arkenu and Ouenat were no longer lost,

and, if my observations proved to be as accurate as I hoped they were,

a good map could now be made of this strip of the Libyan Desert from

Jalo to Furawia.

We spent three full days at Furawia getting used to the damp climate

we had come into and trying to get enough to eat to keep us from

feeling miserable. Dark clouds hovered over our heads much of the

time, and every day it rained. My men gorged themselves with mutton,

but the lack of sugar for the tea and other provisions rather took

the edge off their enjoyment of these feasts.

On June 6 we started south in the afternoon and climbed slowly out

of the valley. We passed many flocks of sheep and cattle going home,

followed by slim girls and boys clad in nothing but a loin-cloth or

strings of beads.

It was quite different from the desert we had come through. We were

following a beaten track and passing frequently small villages of

straw huts, women carrying _hatab_, and other signs of habitation.

Near one of the villages I told the caravan to go ahead and pointed

out to them where we would camp. I followed with my horse. There

were a few points of interest geographically, and I had to take some

observations. As I was nearing the camp I heard voices curiously

upraised, a mixture between men wailing and singing. My first thought

was that some of the men of the caravan had got into trouble with

the natives. I spurred on my horse and as I was approaching the

camp my mind was relieved, for I heard the _tom-tom_ of the drum and

women’s voices singing. It was just after sunset, and in the dusk

I could not distinguish clearly the crowd that was moving toward me,

but soon one of my men came rushing up to tell me they had had the

most cordial reception from the men and women of the village, who

insisted on coming out to receive “the _sheikh_ of the caravan.”

He had hardly broken this news to me when a bevy of young girls,

some singing, others dancing, surrounded my horse, who responded

as befitted a Bedouin horse and started prancing. The women raised

_lu-lias_, and I was urged by my Bedouins to empty gunpowder. The

crowd made way for my horse, and I walked him a short distance off,

turned around, came rushing back, and pulled him up dead. By that

time I had got out my rifle, and as my horse stopped dead I fired my

shot, in Bedouin fashion, at the feet of the first row of beautiful

damsels. They were half frightened and half delighted. Then six of them

surrounded the horse, circling round me, and gave me the _shabaal_;

that is to say, with a sudden twist of the head they whirled their

tresses toward me as a woman of southern Europe might throw a rose. In

response, I put my finger on each girl’s forehead and, holding my

rifle high in the air, twirled it round her head, crying “_Abshir

bil kheir!_” (“Rejoice in the bounty of God!”). We then formed

ourselves into a procession and proceeded to the camp. The moment

they saw me coming surrounded by all those girls the Bedouins fired

in the air in honor of the occasion. The Bedouin is very chivalrous,

and such is his idea of honoring the ladies. Afterward I distributed

scent to all the girls, who went away very happy, and it was a most

cheerful evening in the camp.

The next day we reached Um Buru, thirty-eight kilometers from

Furawia. We camped near the well, and the next morning I was awakened

early by sounds of cattle and sheep coming to water. An hour later

a busy market was being held alongside our camp. We had unwittingly

pitched our tents close by the big tree that marked the center of the

market-place. Only women took part in the market, bringing butter,

leather, mats, maize, cotton, and salt, which they bartered with each

other without the use of money. Meanwhile the men lay about at their

ease and did nothing. As I watched such a scene as this and others

not unlike in the villages of the Sudan, I found myself wondering

whether the black women were not after all better off as slaves in

a Bedouin household. Here they do all the work that is done, caring

for cattle and sheep, doing the housework, and preparing meals and

making the favorite beverage _merissa_ for their men, carrying on the

business of the market—everything. As slaves they would have only

certain circumscribed duties and some opportunity for leisure. As I

turned this over in my mind, however, I seemed to catch something

in the sound of their talk and their laughter that slaves do not

have. Perhaps there is something in the feeling of liberty after all,

even when it is accompanied by drudgery.

[Illustration: THE RECEPTION OF THE EXPLORER AT EL FASHER

The governor of the Darfur Province and his staff welcome the explorer

to the capital of the province]

We stopped at Um Buru for two days. Abdel Rahman Jeddu, _wakil_ of

Mohammedin, the head of the Zaghawa tribe, visited me and brought

sheep and chicken as _diafa_. On the second day we were given an

official welcome, the _wakil_ coming with a retinue of retainers on

horseback beating drums. Mohammedin’s family, in the absence of

the master of the household, sent a lunch of _asida_, vegetables,

_merissa_, and pastry.

The next stage of our journey was a five days’ trek to Kuttum,

129 kilometers to the southward. The weather was generally good,

though hot, with an occasional shower. We traveled as usual in the

early morning and late afternoon. There was a beaten track with

fairly good going, through hilly country covered with dry grass and

small trees. At intervals there were patches which had been burnt in

preparation for being cultivated.

On the third day my messenger to El Fasher arrived, with two

companions, but it was a disappointing meeting. It had taken him five

days instead of four to reach his destination, and he had not brought

the answer to my letter back with him. It was waiting for me, he said,

in the possession of a soldier at Mutarrig Well, twelve hours’

journey from where we were. The soldier also had provisions for us,

but they did us little immediate good at that distance.

There was little for dinner when we camped that night. After dinner

I sent our guide off post-haste with orders to ride all night and

until he reached Mutarrig. There he was to tell the soldier to come

to us as fast as he could.

We started before four the next morning, and in an hour the men

came rushing to me with the news that there was a soldier ahead on

a camel. In a few minutes I had a letter from Charles Dupuis, acting

Governor of Darfur, in the absence of Saville Pasha who had resigned

from the service, and a small supply of rice, flour, tea, and sugar. I

was especially pleased to be handed a supply of cigarettes.

I had not smoked since soon after leaving Erdi. At Ouenat I had

suddenly realized that there were only a few cigarettes left. I

then laid down a strict rule for myself: one cigarette a day after

dinner. It was hard work waiting all day for that brief smoke, but

it was worth it when the moment came. I would get into a sheltered

corner, light the precious cigarette, and shield it carefully from any

breath of wind that might make it burn ever so slightly faster. When

the few cigarettes were gone, there was nothing left but memories

and expectation. Now at last the expectation was gratified with a

vengeance, for I smoked until my throat was sore.

Bukara, with a handful of the newly arrived cigarettes, put on his

long-tasseled red _tarboosh_, got on the guide’s horse, and did a

little _fantasia_ of joy. But it was when we camped at the government

rest-house at Marahig that general rejoicing broke loose with singing

and dancing. The corporal, looking on while the men set the sugar-loaf

on the ground and executed a wild dance about it, thought us all a

little mad.

“Why all this rejoicing?” he demanded.

“Because for a month we have had no sugar, and now our tea is

sweetened again,” said Abdullahi.

Until one has tried going without any sugar whatever, one does not

realize how keenly it will be missed.

The corporal shook his head and smiled. “I must return at once to

Kuttum and bring you more provisions,” he said. “We never realized

that you were so short of food.” Before he left he was kind enough

to go to a camp near-by and bring us a sheep and butter, which were

to be paid for by the _moawin_ of Kuttum, since the seller refused

to accept Egyptian paper money. The corporal then left with letters

from me for Mr. Dupuis and the _moawin_, the deputy Governor of Kuttum.

The provisions which he had brought us were good as far as they went,

but we should very soon be in need of more. I decided to push on at

once. We made our midday halt at the government rest-house at Marahig

Well and our stop for the night only a few kilometers farther on. The

camels were in very bad condition. The backs and sides of some of

them were sore and bleeding, and two camels refused to move until

their loads were taken off. It rained for an hour that evening,

but it could not dampen our spirits. The men sang and danced around

a big fire. The humidity and the smell of the wet grass reminded me

of my walks in English country.

We made an early start the next morning in order to reach Mutarrig

Well for the midday halt. We lunched at the rest-house near the well

and received a visit from the _sheikh_ of Mutarrig, who brought a

few chickens as _diafa_. He wanted us to stop the night so that he

could entertain us properly the next day, but I felt the necessity

of going on as fast as possible.

The camels were getting steadily worse. We had to leave one of them

with the _sheikh_ of the village on the understanding that if it

recovered he was to get a quarter of the price it brought when sold,

while if it died he was not to be held responsible.

An hour and a half after starting the next day another soldier on

horseback appeared. He brought a letter from the _moawin_ of Kuttum

and a small quantity of rice and sugar. They are gratefully received,

for once more we were on short rations and without sugar for our

tea. I gave him a letter to take back to Kuttum. A little later we

camped in the small valley of Boa. In the afternoon, soon after we

had started again, it came on to rain with a strong southeast wind,

and I thought it might be wise to camp until the storm was over. But

through my glasses I made out ahead of us the row of straw huts of

the Markas—the government house—of Kuttum, and spurred on by the

sight we drove the camels faster.

Soon a group of horsemen were seen approaching us, and my Bedouins

impulsively raised a cheer. When I recognized the uniform of Sudanese

troops, it was the most cheering sight that I had seen for many

weeks. Riad Abu Akla Effendi and Nasr El Din Shaddad Effendi, the two

_moawins_ of Kuttum, approached with a detachment of ten soldiers,

the _kadi_, the head clerk, and other officials and notables of

Kuttum. I shook hands warmly with them all, and under their escort

the caravan moved on through the village. As we approached, the Markas

women clothed in white and beating drums greeted us with singing and

“lu-lias.” We settled ourselves in and about the rest-house, and

the women came again to offer greetings. In a long line they sang and

danced, much to the delight of my Bedouins, who asked permission to

empty gunpowder in acknowledgment of the courtesy. I could not refuse

my consent, and one by one, beginning with Bukara, the men performed

the ceremony of singeing the girls’ slippers. The Sudanese women

were not so accustomed to the Bedouin manner of paying homage as the

girls of the northern desert, and flinched a little as the powder

flashed at their feet. But they accepted it all in good part, the

whole line swaying and dancing to the rhythm of the drums while one

by one my men singled them out for the “slipper-singeing honor.”

It was a wonderful reception, and the pleasure of it dispersed like

magic the fatigue and lassitude of the journey.

More hospitality was to come. Four sheep, butter, and fresh vegetables,

to say nothing of sugar, were brought to us as _diafa_ from the

_moawins_ and officials, and we spent a pleasant evening feasting.

Our arrival at Kuttum at this particular moment had seemed to the

inhabitants there an especially auspicious one, for we came with the

first rain of the season.

We stopped there for two days, entertained generously by the _moawins_

in the absence of the inspector, Mr. Arkell, who was at El Fasher.

One afternoon we attended a soccer match between two teams of

soldiers. It was played with energy if not with finesse. At times

a player, striving to give the ball an especially vigorous kick,

would miss it and send his Sudanese slipper shooting high into the

air. The _camaraderie_ between officers and men, playing this not

exactly gentle game together, was interesting to see.

Dinner that night with Riad Effendi and Nasr El Din Effendi, the

_moawins_, was the first meal I had eaten in a house since leaving

Kufra. My hosts gave me Egyptian newspapers to read, the first I had

seen in nearly six months.

We left Kuttum at six o’clock on the morning of June 17, cheered

by the generous hospitality we had enjoyed and the friendly send-off

our friends gave us. The two days’ journey to El Fasher was a

joy-ride. We all felt the thrill and exhilaration of getting in touch

with the world again.

But as I went to bed on the eighteenth I realized with a stab of

regret that this was my last day in the real desert. I thought how I

should miss my men and my camels, the desolateness and the beauty,

the solitude and the companionship; in two words, the desert and

its life. I thanked God for His guidance across this vast expanse

of pathless sand and found myself adding a prayer, half wistfully,

that I might come back to it again.

I had given orders for an early start the next morning. In their

eagerness my men somewhat exaggerated my idea of “early,” but I

was excited myself and did not mind getting under way at half-past two.

Three hours’ march from El Fasher we camped to make

preparations for entering the place. We all shaved and put on

our best clothes. Mr. Dupuis had sent a supply of white cloth to

Kuttum for us, and my men were able to appear once more in decent

raiment. They crowded around my remnant of a mirror to see how they

looked. Rifles were cleaned, and the luggage, which was in a very

shabby state, was tidied as much as possible. I wished that I might

be able to do something for the camels as well, which were thin and

dejected-looking. But rest and attention to their sore backs were

what they needed, and we had no time or facilities for giving them

that. Nevertheless they too seemed to be infected with the spirit

of eagerness felt by all of us and walked forward briskly. Abdullahi

and Zerwali got into their silks, and the caravan moved gaily toward

its destination.

As we reached the outskirts of El Fasher, cheers of rejoicing rose

throughout the caravan. A cavalcade of men in khaki was coming toward

us. I put spurs to Baraka, and he responded willingly. He saw the

horses before us, pricked his ears forward, and dashed toward them.

[Illustration: EL FASHER

The capital of Darfur Province]

Mr. Dupuis came forward on his horse to meet me, and we shook hands

warmly. The greetings were repeated by the English and Egyptian

officers of his staff, and we went on to his house, a part of which he

generously made over to me and the men of my caravan. The weary camels

were promptly taken in hand by Bimbashi Andas, who gave them food,

water, and the medical treatment for their wounds they so much needed.

The officer in charge of the wireless station kindly got me the exact

Greenwich time from Paris by radio. I was pleased to discover that

my chronometer had lost only twenty-three minutes and twenty-three

seconds in eight months.

For ten days I was the guest of Mr. Dupuis and was lavishly entertained

by the officers and officials of the garrison, both English and my own

compatriots, and the notables of the town. Hospitality was showered

upon me, and every kind of assistance that could possibly be needed

was eagerly rendered. This was civilization again. I enjoyed once

more the luxuries of life, especially vegetables and fruits. It is

only when one has gone through the austere régime of the desert that

one looks upon these things as luxuries and not necessities. There

was in particular a brand of prunes, the pride of Major Smith, and

of peculiar lusciousness. He called them “If Winter Comes,” and

I have never tasted their like anywhere.

At last the day came when I must take leave of my companions of the

trek from Kufra. When Bukara and his brother and Hamid and Senussi Bu

Jaber came to my room to say good-by, it was a moment full of real

emotion and crowded with memories. These rugged men of the desert

burst into tears, and I found my own eyes wet. We had been through

thick and thin together and came out fast friends. I could never wish

for better companions on a journey into desolate regions, more able,

more manly, or more loyal.

We read the “Fat-ha,” the sound of the familiar sacred phrases

punctuated by Bukara’s sobbing. I exchanged a final handclasp with

each of them, and we parted, to meet one day, I hope, in that desert

that I love as much as they.

One more camel-trek before me eastward to El Obeid. There I took

train for Khartum and thence home to Cairo, where I arrived on August

1, 1923.

I had been away from home seven months and twenty-three days, having

trekked twenty-two hundred miles across the desert by caravan.

I had determined finally the position of the Zieghen Wells and of Kufra

on the map of Africa, in the placing of which there had been hitherto

errors of one hundred and of forty-five kilometers respectively.

I had also had the great good fortune to put the “lost” oases of

Arkenu and Ouenat definitely on the map of the Libyan Desert.

To A. M. H.

I crave no statue in a public street,

Nor page of history to give my name:

A desert flower on my winding sheet

Is all I ask to mark the way I came.

There were no jewels buried in the sand,

The treasure that I sought was little worth:

I went—but oh, how few will understand—

To tread an unworn carpet of the earth.

Wide spaces called me, and the way was free;

Feet falter not upon a road unknown:

How languish, one who, looking back, can see—

A thousand miles—no footsteps but his own?

Not half a hundred voyagings for gold

Could make me rich as many times I’ve been

When, weary-eyed, I’ve watched the dawn unfold

And spread soft radiances o’er a desert scene.

Thoughts were my treasure; where may thoughts be sold?

My world was empty, but my world was clean.

G. F. FOLEY.

El Fasher,

June 30, 1923.

APPENDIX I

NOTE ON THE CARTOGRAPHICAL RESULTS OF HASSANEIN BEY’S JOURNEY

John Ball, O.B.E., D.SC., Director of Desert Surveys, Egypt

=1. Introduction=

THE cartographical data brought back by Hassanein Bey consist of:

(1) Note-books containing the records of astronomical observations

for the determination of time, latitude, and compass-variation at

nineteen principal camps, with records of watch-comparisons.

(2) A journal giving a continuous record of observed compass-bearings

and estimated distances from Siwa Oasis to Lameina Wells, near El

Fasher, a distance of about 2430 kilometers.

The journal also contains a considerable number of observed

compass-bearings to conspicuous features on either side of the route,

with a few rough trigonometrical estimations of the altitudes of

mountains passed, a large number of readings of an aneroid barometer

and sling thermometer for the estimation of altitudes along the route,

daily observations of maximum and minimum temperatures, observations

on the character of the country passed through, and notes on the

meteorological conditions.

These observational data have been reduced in the Desert Survey

Office, Cairo, and utilized in the preparation of the map on a scale

of 1:2,000,000 which accompanies Hassanein Bey’s account of his

travels. The objects of the present note are, first, to give an account

of the critical examination to which the records were subjected in

the course of the reduction of the observations, so as to enable an

estimate to be formed of the degree of precision which may be fairly

assigned to the geographical positions, altitudes, and other results

used in the construction of the map; and, secondly, to indicate the

additions to existing geographical knowledge concerning a little-known

region of northeast Africa which have accrued from the expedition.

=2. Astronomical Determination of Local Time=

Theodolite observations of altitudes of the sun or of stars were made

at all the principal camps for determining the error on local mean

time of the half-chronometer watch which was used in the latitude

observations. In all, thirty-four complete time determinations were

made at seventeen camps. The observations were made with a three-inch

Troughton & Simms theodolite, the vertical circle of which could be

read by two verniers to 1′, and which was provided with a sensitive

level on the microscope arm. The theodolite was invariably set up in

the magnetic meridian by its trough compass, and the method used was

to note the times of passage of the sun’s limb or of the star over

each of the three horizontal wires of the stadia-graticule, reading the

level and circle at each pointing, face-right and face-left. In the

case of stars, the magnetic bearing of the star was also noted from

the horizontal circle, and a note made of the color and brightness

of the star, for the identification of the stars subsequently in the

office, and thus to free the observer from the necessity of knowing

the stars’ names. The barometer and thermometer were carefully read

at each observation for calculating the refraction.

No difficulty was experienced in subsequently identifying the stars. In

only a single case was it found necessary to reject an observation, and

this because the observer had accidentally sighted different stars on

the two faces of the instrument. On many days two or more observations

were taken at the same place, and comparisons of the results at these

places indicated that the observations are remarkably accurate for so

small an instrument. In seven cases where the sun has been observed

shortly before sunset and a star soon after sunset, for example, the

maximum difference between the results given by the two observations

is only seven seconds, while the average is under four seconds. It is

thus apparent that the precision of the time observations is amply

sufficient to insure that no sensible error in the latitudes can be

due to errors of the adopted local times.

As the only use made of the time observations in the preparation of

the map has been in the determination of latitude, it would serve no

useful purpose to give a list of the watch errors. But it may interest

future geographers, undertaking long desert journeys, to note some of

Hassanein Bey’s experiences in the transport of watches, and the

hazard of relying on constancy of rate for long periods with even

the best watch.

Of the six watches carried, only a single one remained in going order

throughout the journey. The timekeeper which thus successfully resisted

the vicissitudes of the seven months of desert travel was fortunately

the one with which Hassanein Bey took all his observations, and was

carried in his pocket during the entire journey; it was a large-sized

half-chronometer “explorer’s” watch of English manufacture,

with a dust-proof cap to the winding mechanism. It had been awarded an

“especially good” certificate at the National Physical Laboratory

of England, and was consequently the most expensive of all the six

watches taken on the journey. Even this watch failed to maintain a

sufficiently constant rate to be of any service in the determination

of longitudes, though it amply sufficed for the latitudes, even in

two cases when reliance had to be placed on the constancy of its rate

for one or two days owing to latitude alone being observed without

corresponding observations for local time. Thus, for instance, the

following were the average rates of the principal watch deduced from

local time observations at places of previously known latitudes:

RATE OF PRINCIPAL WATCH

Sollum to Siwa Dec. 29-Jan. 13 15 days losing 5.8 secs.

Siwa to Jaghbub Jan. 13-Jan. 20 7 “ “ 0.1 “

Jaghbub to Furawia Feb. 14-June 5 111 “ “ 7.7 “

Furawia to Um Buru June 5-June 8 3 “ “ 6.6 “

Um Buru to El June 8-June 26 18 “ “ 9.4 “

Fasher

El Fasher to El June 30-July 15 15 “ “ 9.4 “

Obeid

The above table fails, however, to bring out fully the actual

variations of the watch. So long as the other five watches remained

in order, Hassanein Bey made frequent comparisons with his principal

watch, and between March 21 and 23 there is strong evidence that

the principal watch made an abnormal gain of about fifty seconds. A

similar abnormal gain of twenty-nine seconds by the principal watch is

evidenced in the twenty-four hours between comparisons of March 24 and

25. Both these abnormalities occurred between Jalo and El Harrash,

at an early stage of the journey, while all the watches appeared

to be behaving tolerably well, and it is quite possible that other

abnormalities occurred at later stages, when, owing to some or all

of the other watches having stopped or broken down, no satisfactory

control by comparison was possible.

Of the other five watches carried, one was an English half-chronometer,

similar to the principal watch but of smaller size; three were

high-class Swiss lever (“Peerless”) watches with very tight-fitting

cases; and the fifth was a small Swiss lever-watch with luminous

dial, carried on the wrist for noting the times of marching. The small

half-chronometer stopped on April 3, after going for over four months;

and though it was restarted, its rate changed considerably after the

stoppage. The three “Peerless” watches, though they failed to

continue going to the end of the journey, showed by no means a bad

record. One was found stopping and unreliable on May 6, after going

for over five months; the two others continued to go for over a month

longer; and so far as can be judged from the comparisons made on the

route, their variations of rate were about of the same order as those

of the half-chronometers. The wrist-watch, from the manner in which it

was carried, was of course liable to much greater variations of rate,

and was occasionally reset by the principal watch; but it kept going

till nearly the end of the journey.

As regards dust-resisting power, which must always be one of the

principal aims in selection of watches for desert exploration, there

appears to be nothing to choose between good English half-chronometers

and the highest class of Swiss watches, the cases of the latter being

remarkably close-fitting. The most probable cause either of stoppage

or of abnormal changes of rate appears to be the sudden shocks which

may arise either to a watch carried on the person when jumping on or

off a camel, or to one carried in the baggage by sudden movements of

the camel. The most likely explanation of the abnormal gains of the

principal watch for short periods on the two occasions above noted

would seem to be that, owing to a jerk in mounting or dismounting,

two contiguous coils of the hair-spring may have been made to touch

each other for a short time, with consequent temporary shortening of

the period of vibration of the balance-wheel. It is noteworthy that

the watch which remained going throughout the journey was the largest

of all those taken, and its greater resisting-power may have been to

some extent due to its size, permitting of greater strength in its

component parts.

=3. Astronomical Determinations of Latitude=

Observations for latitude by altitudes of the pole-star were carried

out on thirty-five nights at nineteen principal camps, using the same

three-inch theodolite as was employed for the time-observations. Three

readings of altitude were made on each face, using each of the

three horizontal stadia-wires in turn, the corresponding times

being noted on a half-chronometer watch whose error on local time

was accurately known from sun or star-observations carried out just

before the latitude-observation. Particular care was taken with the

level-adjustment, and the air-pressure and temperature at the time

of the observation were recorded.

The following table gives the results of the observations:

ASTRONOMICAL LATITUDES

° ′ ″

Sollum 4 nights Lat. 31 35 9 N.

Siwa 1 “ “ 29 12 41 “

Jaghbub 5 “ “ 29 44 26 “

Camp near Jalo 1 “ “ 29 11 56 “

Jalo (El Erg) 1 “ “ 29 2 33 “

Buttafal 1 “ “ 28 54 26 “

El Harrash 1 “ “ 25 26 29 “

Taj 6 “ “ 24 13 47 “

Arkenu 2 “ “ 22 12 32 “

Ouenat 1 “ “ 21 52 29 “

Erdi 1 “ “ 18 35 39 “

Agah 1 “ “ 17 52 38 “

Enebah 1 “ “ 17 21 24 “

Bao 1 “ “ 16 28 24 “

Furawia 2 “ “ 15 21 51 “

Um Buru 2 “ “ 15 3 57 “

Kuttum 1 “ “ 14 12 15 “

El Fasher 2 “ “ 13 38 3 “

El Obeid 1 “ “ 13 10 51 “

Of six of the above places (Sollum, Siwa, Jaghbub, Kuttum, El

Fasher, and El Obeid) the latitudes are accurately known from the

Egyptian and Sudan official surveys, and the agreement in these

cases is very satisfactory, though a very close comparison is not

generally possible owing to uncertainty as to Hassanein Bey’s

precise observation-spot. At Jaghbub, Hassanein Bey records that

his observation-spot was 200 meters S.S.W. of the dome of the

mosque. Applying the corresponding difference of latitude (− 6″)

to my own determination of the latitude of the dome in 1917 (29°

44′ 41″) we obtain 29° 44′ 35″, showing a difference of only

9″ from Hassanein Bey’s observed latitude.

A further test of the degree of precision of the latitude-observations

can be made by comparison of the latitudes found for the same camp

by observations taken on different nights. The following gives the

average deviation of a single observed latitude from the mean at all

the camps where two or more observations for latitude were made:

″

Sollum 4 nights Av. dev. 8

Jaghbub 5 “ “ 40

Taj 6 “ “ 12

Arkenu 2 “ “ 6

Furawia 2 “ “ 8

Um Buru 2 “ “ 23

El Fasher 2 “ “ 6

It thus appears unlikely that any observed latitude can be as much

as 1′ in error, and consequently in the preparation of the map,

Hassanein Bey’s observed latitudes have been accepted as fundamental

data for all the places for which no previous determinations are known

to exist, viz., El Harrash, Taj, Arkenu, Ouenat, Erdi, Agah, Enebah,

and Bao. His latitudes for Jalo (El Erg), Bir Buttafal, and Furawia

have also been adopted for the map, the first because it is possibly

better than that of Rohlfs, with whose mapped position it is however

in very close agreement; the second because while differing by about

2′ from Rohlfs’s value (28° 36′ 22″) it is doubtless more

exact, because it checks admirably well with Hassanein Bey’s dead

reckoning; and the third because, although the position of Furawia

is shown on the Sudan maps, it is outside the present limits of the

Sudan triangulation and is possibly liable to some slight error.[1]

=4. Observations of Compass-Variations=

For finding the pole-star easily when the sky was not very dark or was

partially obscured by clouds, and also for obtaining the approximate

bearings of time-stars for their subsequent identification, the

theodolite was invariably set up in the magnetic meridian by its

trough-compass, and the magnetic bearing of the pole-star was read on

the horizontal circle after each latitude-observation and the time

noted. In this way approximate compass-variation was determined at

each camp, with the following results:

VARIATION OF THE COMPASS

° ′

Sollum Dec., 1922 3 obs. 2 34 W.

Siwa Jan., 1923 1 “ 2 42 “

Jaghbub Feb., 1923 5 “ 2 25 “

Near Jalo March, 1923 1 “ 4 12 “

Jalo (El Erg) “ “ 1 “ 4 5 “

Buttafal “ “ 1 “ —

El Harrash “ “ 1 “ 3 48 “

Taj April, 1923 6 “ 3 32 “

Arkenu “ “ 2 “ 3 25 “

Ouenat “ “ 1 “ 3 32 “

Erdi May, 1923 1 “ 3 57 “

Agah “ “ 1 “ 4 0 “

Enebah “ “ 1 “ 4 21 “

Bao “ “ 1 “ 4 59 “

Furawia June, 1923 2 “ 4 32 “

Um Buru “ “ 2 “ 3 25 “

Kuttum “ “ 1 “ 4 26 “

El Fasher “ “ 2 “ 2 51 “

The method of estimating the compass-variation with the theodolite is,

of course, only rough; but the values found are probably correct at

most places within half a degree, and they serve to show that there

is no likelihood of any serious errors of dead-reckoning owing to

local irregularities of the compass-variation. They have accordingly

been utilized in reduction of the compass-bearings of the traverse to

true bearings over the major portion of the route, where no previous

determinations exist, and where in consequence the distribution of

the isogonic lines is not known with any exactitude.

=5. Longitudes=

The probability of some watches breaking in the course of seven

months’ travel had been foreseen, and from the outset it appeared

improbable that any use could be made of the watches in the direct

determination of longitude of so long and difficult a journey. We

had decided accordingly to depend ultimately on dead-reckoning

for longitude, making every effort to obtain an unbroken chain of

compass-bearings and estimated distances between Jaghbub and some known

place in the Sudan, the bearings to be taken with a good compass with

all possible precision, at very frequent intervals, and the estimates

of distance to be carefully made each day from the marching time of

the baggage-camels, assuming a normal rate of 4 km. per hour over

average desert, and making allowance for the variations in speed over

ground of varying character. The journey being predominantly north to

south, the estimates of distance could mostly be well controlled by the

latitudes, while errors of bearing would not be cumulative, and would

tend to cancel out over any considerable stretch of route. The primary

reason for taking six watches was therefore not to determine longitude,

for which at best they could afford only somewhat uncertain values,

but to make sure of at least one watch being available throughout the

journey for latitude-observations, without which no proper control

of the all-important distances could be obtained.

The doubts about the possibility of safely transporting the watches

proved justified, for all but one broke down before the end of the

journey. But fortunately on the one hand the watch which survived

sufficed amply for the determination of latitude (though its rate

was insufficiently constant for it to be used uncontrolled in finding

longitudes), and on the other hand the program of a continuous chain

of very careful bearings and estimation of distances was scrupulously

adhered to from the departure of the caravan from Jaghbub, the

last known place in Egypt, to Furawia, the first known place in the

Sudan—a journey of 2430 kilometers—and from this chain of bearings

and estimated distances, combined with the observed latitudes, it

was possible to estimate the longitudes of all places on the route

with a fairly high probability of accuracy.

For the estimation of the longitude of Jalo (El Erg) a slightly

different procedure was followed from that adopted for the other

principal camps on the route. It will be noticed from the map that the

general direction of the march from Jaghbub to Jalo was predominantly

from east to west, instead of from north to south as in the rest of

the journey. Consequently the observed latitudes do not afford so

good a means of correcting the estimated distances in this stretch as

elsewhere. But fortunately the observed latitude at Jalo does enable

us to correct the previous estimation by Hassanein Bey (in 1920) of

the distance of that place from Jedabia, and this combined with the

then observed bearings would lead to one value for the longitude for

Jalo, while if we can assume the accuracy of the estimated distances

from Jaghbub to Jalo, we may use the observed latitude of the latter

place to correct the bearings and thus arrive at another value for

its longitude.

From careful consideration of all the available data, the two methods

appear likely to be about equal in degree of approximation. The

position at present accepted for Jedabia (Lat. 30° 48′ 10″

N., Long. 20° 13′ 30″ E.) is open to a little uncertainty,[2]

and the bearings taken by Hassanein Bey on his former expedition are

probably a little less accurate than those of the present one. On the

other hand, the estimations of the distances from Jaghbub to Jalo,

as gaged by the latitude-control of the other portions of the route

of the present expedition, are remarkably close to the truth, while

a uniform correction to his bearings of less than half a degree would

swing his dead-reckoning position for Jalo on to its observed parallel

of latitude.

For the longitude of Jalo on the map I have therefore taken the mean

of the two longitudes found (1) by assuming Hassanein Bey’s bearings

correct from Jedabia and correcting his distances by the latitudes,

and (2) by assuming his distances from Jaghbub correct and using the

observed latitudes to correct his bearings. The results are:

° ′ ″

(1) From Jedabia, long. of Jalo (El Erg) 21 29 48

(2) From Jaghbub “ “ “ 21 26 19

--------

Adopted mean 21 28 3

It may be remarked in passing that the result places Jalo almost

precisely where it is shown on Rohlfs’s map of 1880.

As regards the longitudes adopted for the other principal camps

along the route, the procedure has been as follows. The route was

divided into the following nine sections between principal camps

where latitudes had been observed: Jalo, El Harrash, Taj, Arkenu,

Ouenat, Erdi, Agah, Enebah, Bao, Furawia; and the compass-traverse for

each section was plotted on a scale of 1:500,000 from the recorded

bearings and estimated distances. A true meridian was then drawn

on each section from the mean of the observed compass-variations at

its two ends, and the total difference of latitude of each section

was scaled off and compared with the difference of latitude given

by the latitude-observations. This comparison gave, of course, the

average error of estimation of distance along each section, assuming

the bearings correct. The results of the comparison for the various

sections are tabulated below:

CORRECTION TO ESTIMATED DISTANCES

_True _Correction

_Plotted difference _True- to

_Section of difference from plotted estimated

traverse_ of latitude_ latitude- diff. lat._ distances_

observations_

km. km. km. %

Jalo-El 375.0 399.0 + 24.0 + 6.4

Harrash

El Harrash-Taj 131.5 134.2 + 2.7 + 2.1

Taj-Arkenu 217.7 223.7 + 6.0 + 2.8

Arkenu-Ouenat 36.0 37.0 + 1.0 + 2.8

Ouenat-Erdi 369.0 363.2 − 5.8 − 1.6

Erdi-Agah 75.6 79.2 + 3.6 + 4.8

Agah-Enebah 57.0 57.5 + 0.5 + 0.9

Enebah-Bao 99.0 97.7 − 1.3 − 1.3

-----

Mean error of estimation of distances, per cent 2.6

The average error of distance-estimation in each section of the

route having been thus found, the next step was to scale off the

various departures from the plotted traverses, correcting for the

errors of distance-estimation, and then to convert the departures

into differences of longitude. When this was done, the resulting

total difference of longitude between Jalo and Furawia was 2° 25′

55″. But assuming the true longitude of Jalo to be that found above,

and the true longitude of Furawia to be as shown on sheet 53 D of

the 1:250,000 Sudan survey map of 1921,[3] we have:

° ′ ″

Longitude of Jalo 21 28 3

Longitude of Furawia 23 38 10

------------

Difference 2 10 7

So that the difference of longitude found by the dead-reckoning

requires correction by 15′ 48″. This correction, which implies an

average error in the observed compass-bearings of less than a degree,

and a negligible correction to the adjusted distances, was distributed

along the entire traverse in proportion to the difference of latitude

between the principal camps, leading to the finally adopted longitudes

shown in the following table:

CONCLUDED LONGITUDES

_Dead-reckoning _Further _Concluded

corrected by correction_ longitude_

the latitudes_

° ′ ″ ′ ″ ° ′ ″

Jalo — — 21 28 3 E.

El Harrash 22 15 5 E. 4 10 22 10 55 “

Taj 23 29 5 “ 5 34 23 23 41 “

Arkenu 24 52 10 “ 7 55 24 44 15 “

Ouenat 25 2 34 “ 8 18 24 54 16 “

Erdi 23 22 34 “ 12 5 23 10 29 “

Agah 23 28 49 “ 12 54 23 15 55 “

Enebah 23 25 58 “ 13 30 23 14 28 “

Bao 23 16 18 “ 14 31 23 1 47 “

Furawia 23 53 58 “ 15 48 23 38 10 “

In attempting to estimate the probable degree of accuracy of the

concluded longitudes, we are faced with the difficulty that while

we may be certain that the _average_ error of the compass-bearings

was less than 1°, which average error has been allowed for in the

adjustment, we have no proof that in some of the individual sections

the errors may not have been considerably greater. But in view of

the great number of the observed compass-bearings (339) which make up

the directional data of the 1754 kilometers of traverse from Jalo to

Furawia (an average of thirty-eight observed bearings for each of the

nine sections), and bearing in mind also the remarkable accuracy of the

estimations of distance as evidenced by the latitude-observations,

it would seem unlikely that any of the above-adopted longitudes

for the principal camps can be in error by more than three or four

miles. This implies a degree of accuracy which it would have been

difficult to insure by transport of even a considerable number of

chronometers over a land journey lasting more than three months. It

may, I think, be concluded that no better values for the longitudes

can be obtained without the aid of wireless time-signals.

=6. Altitudes above Sea-level=

For the barometric estimations of altitudes above sea-level, a two-inch

aneroid by Steward was used. This instrument, which was one of two

specially made for the expedition, was very carefully compensated

for temperature, and provided with a fairly open pressure-scale, a

millimeter of pressure being represented by very nearly a millimeter

of actual scale-length, so that estimations to half-millimeters of

pressure could be readily made.

The aneroid was read morning and evening at each camp, and at

numerous other points on the route, the air-temperatures being as a

rule recorded at the same time, as given by sling-thermometer. The

aneroid behaved very satisfactorily throughout the journey. There had

unfortunately been no opportunity of testing the instrument before

Hassanein Bey’s departure, but it was in perfect order on his return,

and was then tested in the laboratory of the Physical Department

at Cairo, when it was found to require the following corrections

(at about 25° C.):

Pressure, mm. 760 750 740 730 720 710 700 690

Correction, mm. − 2.3 − 2.3 − 2.3 − 2.1 − 1.4 − 1.1 − 0.1 + 0.6

[Continued]

Pressure, mm. 680 670 660 650

Correction, mm. + 1.7 + 2.0 + 2.8 + 2.9

That the above corrections had remained sensibly constant throughout

the journey is rendered extremely probable by the close agreement

noted further on (p. 329) between the levels found for Jalo directly

from the aneroid readings (corrected, of course, on the assumption

of constancy of the table) and those found indirectly from readings

of the mercurial barometer in the meteorological station at Siwa.

The first step in the calculation of the barometric levels

was to collect the whole of the readings of the barometer and

sling-thermometer at each of the nine principal camps, where a

halt of at least several days had been made, and a considerable

number of readings taken. The means of all the recorded pressures

and air-temperatures were taken for each of these principal camps,

and the pressure corrected for instrumental error from the table

above given. The readings being taken at various times of the day,

the diurnal variation of pressure could safely be neglected, as it

would most probably disappear on taking the mean of the readings. To

allow for the annual variation, the mean pressures were next reduced

to the mean of the year by applying a correction based on the mean of

the normal annual variations at Siwa and El Obeid, as found from the

recent volume of “Climatological Normals” issued by the Physical

Department of Egypt and shown in the following table:

CORRECTIONS TO REDUCE MONTHLY MEAN PRESSURES TO ANNUAL MEANS

_Jan._ _Feb._ _March_ _April_ _May_ _June_ _July_

mm. mm. mm. mm. mm. mm. mm.

Siwa − 3.4 − 2.0 − 1.9 + 0.9 + 0.9 + 2.7 + 3.5

El Obeid − 1.2 + 0.7 + 0.3 + 1.2 + 1.0 + 0.6 0.0

----- ----- ----- ----- ----- ----- -----

Mean − 2.3 − 1.4 − 0.8 + 1.0 + 1.0 + 1.6 + 1.8

A further correction to allow for the distribution of the sea-level

isobars over the region traversed was desirable, but no sufficient

data exist for estimating its amount; the distribution is, however,

probably nearly linear, and such a distribution was approximately

allowed for by assuming the previously accepted levels at Siwa (− 17

m.) and El Fasher (793 m.) to be correct and distributing any residual

difference found by the otherwise corrected barometer readings between

these two places uniformly among the different sections.

The difference of height corresponding to each difference of

mean corrected barometer-readings was calculated by the tables of

_Barometrische Höhenstufen_ in Jordan’s “Mathematische und

Geodätische Hülfstafeln,” for the air-temperature corresponding

to the mean of the thermometer-readings at the two ends of the line.

The adopted levels of thirteen principal camps as found in the

above manner are tabulated below. It is interesting to note that the

residual difference of height which had to be distributed between

Siwa and El Fasher, and which is presumably mainly due to systematic

pressure-gradient, was sixty-three meters, corresponding to a normal

fall of sea-level pressure between the two places of about 5 mm.,

and this is from other considerations probably very near the truth;

also that the resulting adjustment which had to be made in the levels

in any single main section of the route did not exceed five meters.

CONCLUDED ALTITUDES ABOVE SEA

_Diff.

_Number _Mean _Mean of _Diff. _Altitude

of pressure tempera- height of above

obser- (correct- ture_ from height sea-

vations_ ed)_ Jordan’s (adjust- level_

tables_ ed)_

mm. ° C. meters meters meters

Siwa 4 762.6 12 — — − 17

Jaghbub 50 757.7 15 + 54 + 49 + 32

Jalo 18 754.7 17 + 34 + 29 61

El Harrash 6 732.8 23 + 254 + 249 310

Taj 31 718.5 19 + 170 + 165 475

Arkenu 12 708.0 31 + 128 + 123 598

Ouenat 14 706.3 31 + 21 + 18 616

Erdi 7 683.3 31 + 295 + 290 906

Agah 3 695.2 34 − 157 − 162 744

Bao 5 677.7 33 + 230 + 225 969

Furawia 11 685.8 31 − 107 − 112 857

Um Buru 8 679.5 30 + 83 + 78 935

Kuttum 5 660.2 24 + 254 + 249 1184

El Fasher 5 689.7 31 − 386 − 391 793

After thus determining the levels for the principal camps, those

of intermediate camps and other places were computed in a similar

manner, adjusting each section to the adopted levels at its terminal

points. The maximum adjustment which it was found necessary to apply

to the difference of height given by the barometer between points a

day’s journey apart was five meters, and the average three meters.

An exception was made in the stretch between Jaghbub and Jalo,

where no intermediate levels were adopted for the map, owing to the

extremely unstable state of the atmosphere during the journey between

these two places; sand-storms of great violence occurred on several

days of marching, with such rapid fluctuations of air-pressure that

no heights could safely be deduced from the barometer-readings.

As regards the degree of reliability of the deduced levels, some little

uncertainty exists in the levels adopted for the terminal points Siwa

and El Fasher, while the temperature-compensation of the aneroid has

not been tested and may not be quite perfect. Taking everything into

account, it may be estimated that the levels of the principal camps

are probably correct to within about twenty meters, while those of

the intermediate camps and other points, for which only one or two

readings of the barometer are available, may possibly be in error by

twice that amount.

=7. Summary of Principal Geographical Positions and Levels=

_Latitude _Longitude _Meters _Remarks_

N._ E._ above

sea_

° ′ ″ ° ′ ″

Jaghbub (mosque) 29 44 41 24 31 11 32 Position from

previous

determination

by Dr. Ball.

Jalo (El Erg) 29 2 33 21 28 3 61

Bir Buttafal 28 54 26 21 45 15 98

El Harrash Well 25 26 29 22 10 55 310

(Zieghen)

Taj (Kufra) 24 13 47 23 23 41 475

Boema (Kufra. 24 13 8 23 24 40 400 Short compass

Rohlfs’s camp) traverse from

Taj

Arkenu 22 12 32 24 44 15 598

Ouenat 21 52 29 24 54 16 616

Erdi (camp 8 km. 18 35 39 23 10 29 906

north of well)

Agah 17 52 38 23 15 55 744

Enebah 17 21 24 23 14 28 1100

Bao 16 28 24 23 1 47 969

Furawia 15 21 51 23 38 10 857 Longitude

from Sudan map

=8. Construction of the Route Map on Scale 1:2,000,000=

In the process of utilizing the dead-reckoning for the determination

of the longitudes of the principal camps, the whole route had been

provisionally plotted on to a scale of 1:500,000 direct from the

field-books, on a series of sheets each comprising one section of

the route. To these plottings of the actual route were now added

the computed levels of all camps, the geographical features fixed by

cross-bearings on either side of the route, and notes on the nature

of the ground. The various sections thus provisionally mapped on 1:

500,000 were then reduced to the scale of 1:2,000,000, allowance

being made for the small departures of the original plottings from the

1:500,000 scale as found by the latitude-observations, and the various

sections so reduced were drawn in on the final map between the finally

adopted positions of the principal camps. It was found practicable

to show all the principal geographical features on the final scale,

though many notes on the nature of the ground had perforce to be

omitted in order not to overcrowd the map. These notes are however

carefully preserved on the 1:500,000 manuscript sectional maps in

the Desert Survey Office in Cairo, so as to be available for future

reference, while the principal of them are incorporated in Hassanein

Bey’s narrative of the expedition.

The main portion of the route, namely that from Jaghbub to Furawia,

has been mapped entirely from Hassanein Bey’s journals and

note-books. The portions of his route from Sollum to Jaghbub in the

north, and from Furawia to El Obeid in the south, have been copied

from the latest official survey maps of Egypt and the Sudan, as being

more accurate than any route survey could be.

The fixing of the positions of El Harrash and Taj by Hassanein Bey’s

observations has enabled the course of his former expedition to Kufra

(with Mrs. Forbes) in 1920-21 to be delineated more accurately than

was possible from the original records of that journey, which were

unaccompanied by any astronomical observations; and the course of

the former route, adjusted to newly determined positions, has been

indicated on the new map by a dotted line.

=9. Additions to Geographical Knowledge Resulting from the Expedition=

=Jalo.=—The first portion of Hassanein Bey’s route from Jaghbub to

Jalo appears to be identical with that trodden by Rohlfs in 1869. At

Gara Matan Sidi, about half-way between Jaghbub and Jalo, the track

forks and Hassanein Bey went by the northern (Zawaiya) branch, which

passes Hiseila Wells and enters Jalo from a more northerly direction

than the southern (Majabra) branch taken by Rohlfs.

Hassanein Bey’s position for Jalo is almost identical with that of

Rohlfs, but peculiar interest attaches to the former’s determination

of its level at sixty-one meters above sea. Rohlfs, visiting the place

in 1869 and 1879, had found the aneroid to indicate a level below

the sea in 1869, and above it in 1879, and had ultimately concluded

that both Aujila and Jalo lay about at sea-level.[4] Hassanein Bey’s

determination is based on ten days’ aneroid readings and comparison

with Siwa, and it is noteworthy that exactly the same altitude

(sixty-one meters) for Jalo results whether the comparison is made

with the readings of the standard barometer in the meteorological

station at Siwa during the same period, or with the readings taken by

Hassanein Bey with the same aneroid on four days at Siwa two months

earlier (allowance being made, of course, for the annual variation of

pressure over the intervening period). There can, I think, be hardly

any doubt of the greater accuracy of Hassanein Bey’s determination,

since it is unlikely that Rohlfs’s readings extended over so long a

period, and it is practically certain that no comparisons were made

by him with simultaneous observations at a place of known level. It

should however be mentioned that Hassanein Bey’s level probably

refers to a somewhat higher observation point than that of Rohlfs;

for owing to sand-drifts enveloping the houses, the inhabitants of El

Erg are gradually rebuilding their dwellings on higher ground, and

his observations were taken in one of the most recently constructed

of these. Another point worthy of remark is that although Hassanein

Bey’s determination is to a certain extent checked by the exact

agreement of the two methods of comparison above referred to, the

day-to-day variations of pressure observed at Jalo are much in excess

of those at Siwa during the same ten-day period. The extreme range

shown by the aneroid at Jalo was 10 mm. against 5 mm. of the standard

barometer at Siwa, and the 7 mm. average difference of pressure between

the two places for the ten days of comparison, which has been used to

calculate the new value of the level, is the mean of difference ranging

from 1 to 12 mm. on different days. The relatively great variability

of atmospheric pressure at Jalo, which readily explains the discordant

results noted by Rohlfs on different dates, may be closely connected

with the sand-storms which are so frequent in the neighborhood.

=Bir Buttafal.=—Bir Buttafal (“Battifal” of Rohlfs) is of

importance as being the last watering-place for caravans proceeding

on the weary desert march of nearly 400 km. to Zieghen. The position

found for Bir Buttafal by Hassanein Bey agrees fairly well with that

given by Rohlfs:[5]

_Meters

_Lat. N._ _Long. E._ above

sea_

° ′ ″ ° ′ ″

Bir Buttafal, Hassanein Bey 28 54 26 21 45 15 98

Bir Buttafal, Rohlfs 28 56 22 21 44 10 58

-------- -------- ----

Difference 1 56 1 5 40

=Zieghen= (“Sirhen” of Rohlfs).—Zieghen is the name of a

district containing numerous wells. It is not inhabited, but is of

great importance as lying on the main caravan route from Jalo to

Kufra. The principal well used by the caravans is El Harrash. Rohlfs

did not visit Zieghen; he traveled from Jalo to Kufra by the more

westerly track through Taiserbo and Buseima, and the position shown for

Zieghen on his map, which was based merely on his guides’ statements,

is about 100 km. too far to the east-northeast.

As the journey from Jalo to Kufra by any future traveler is likely

to be undertaken in the winter, when the question of fuel is second

only to that of water, it is worth noting that the first _hatab_

(fire-wood) is met with at about 342 km. after leaving Bir Buttafal,

and 52 before reaching El Harrash Well. In an emergency water may be

got at Matan Abu Hosh, the old well of Zieghen, about 18 km. before

reaching El Harrash; but El Harrash yields better water, and being

the regular halting-place of the caravans, the water can usually be

obtained there without digging; hence, unless the caravans are very

thirsty they usually prefer to go on to El Harrash rather than make

a halt at the old well. Excellent water can be got anywhere in the

neighborhood of El Harrash by digging to a depth of three or four

feet. From El Harrash to Buseima is about 54 km. in a direction a

little west of south, and from El Harrash to Taj, the principal town

of Kufra proper, is 182 km. in a southwesterly direction.

=Taiserbo.=—Taiserbo, the most northwesterly oasis of the Kufra

group, has not, so far as is known, been visited by any traveler since

Rohlfs’s day. Its position was however indicated to Hassanein Bey

as lying between 70° and 80° west of north from El Harrash, at a

distance of 60 to 70 km. This indication would place Taiserbo very

nearly in the position which Rohlfs assigned to it. Rohlfs’s position

for his camp at Kasr Djrangedi is probably therefore substantially

correct, though it is likely that the oasis is in reality less

extensive than shown on his map.

=Buseima.=—Although Buseima was not visited by Hassanein Bey on this

occasion, his fixation of the position of El Harrash, in combination

with his former rough compass-traverse from that place to Buseima

with Mrs. Forbes in 1921, permits of a fair approximation for its

position. Hassanein Bey’s estimates of distances and bearings on

his former journey (adjusted by his recently observed latitudes at

El Harrash and Taj) give his camp in Buseima as being 60 km. from

El Harrash in a direction of 5° east of true south, and from his

camp to that of Rohlfs (Ain El Nusrani) was roughly about 15 km. in

a true west-northwesterly direction. Adopting Hassanein Bey’s

recently fixed position for El Harrash, this would give a position

for Rohlfs’s camp about 30 km. southwest by south of where Rohlfs

placed it, as is shown by the following comparison:

_Lat. N._ _Long. E._

° ′ ″ ° ′ ″

Buseima (Rohlfs’s camp) from

Stecker’s observations 25 11 42 22 15 0

Buseima (Rohlfs’s camp) from

Hassanein Bey’s estimation 24 38 11 22 5 46

-------- --------

Difference 13 31 9 14

It would hardly seem possible that Hassanein Bey can have made so

large an error as 25 km. in his former estimation of the distance

of Buseima from El Harrash, and hence it would appear reasonable to

think that there was some error either in Stecker’s observation or

(what is more likely) in his reduction of it. This point is referred

to further on in the discussion of the position of Boema (p. 334).

=Kufra= (Kebabo of Rohlfs).—The name “Kufra” is now generally

applied, not to the whole of the Kufra group of oases as was done

by Rohlfs in 1879, but specially to the area called Kebabo by that

traveler.

The seat of local government and principal settlement is the walled

town of Taj, situated on a rocky cliff overlooking the depression of

the oasis proper which lies to the south and contains the villages of

Jof, Buma, Boema, El Zurruk, Talalib, and Tollab. Hassanein Bey carried

out latitude observations at Taj, and proceeded 3 km., on a bearing

of 16° west of south, to Jof, from which place he made very careful

estimations of the distances and bearings of the other villages of

the oasis, which has enabled their relative positions to be plotted on

the map with much closer approximation than had hitherto been possible.

Considerable interest attaches to the position of Boema, the

easternmost village of Kufra, for it was here that Stecker camped

with Rohlfs and made his observations for latitude and longitude in

1879. Hassanein Bey found Boema to lie 2 km. from Taj, in a direction

54° east of true south. Accepting his determination of the position

of Taj, this leads to the following position for Boema as compared

with that given by Rohlfs:

_Lat. N._ _Long. E._

° ′ ″ ° ′ ″

Boema, according to Hassanein Bey 24 13 8 23 24 40

“ “ Rohlfs[6] 24 31 38 23 12 40

-------- --------

Difference 18 30 12 0

Hassanein Bey thus places Boema some 40 km. south-southeast of the

position assigned to it by Rohlfs from Stecker’s observations. The

remarkable thing about this large discrepancy is that it is chiefly in

the latitude, which was directly observed by Stecker at Boema itself,

and by Hassanein Bey at Taj, only 2 km. away from Boema. I have not

been able to find any details of Stecker’s observations, except

that they were carried out with a “prismatic circle.” But I have

subjected the original records of Hassanein Bey’s observations for

time and latitude at Taj to very careful examination, and there is

overwhelming evidence that his latitude for that place cannot be in

error by more than 1′. He observed the altitude of Polaris at Taj on

no fewer than six different nights, with a watch whose error on local

time was accurately known from sun and star observations carried out

on the same dates. From the internal evidence of the observations

themselves, the watch-error at the time of sighting Polaris cannot

on any occasion have been uncertain by more than two seconds,

which would not, of course, sensibly affect the latitude found; the

recorded magnetic bearing of the star sighted, as well as its rate

of apparent motion, proves that the star used for latitude in each

case was really Polaris; and the greatest difference of any single

observed latitude from the mean of the six nights’ observations

was only 15″, the average departure of a single observation from

the mean being 12″. Hassanein Bey’s latitude of 24° 13′

47″ for Taj can therefore be unhesitatingly accepted as correct

within 1′; and since there is not room for an error of even this

amount in his estimation of the short distance of Boema from Taj,

it becomes absolutely certain that Rohlfs’s latitude for Boema is

over a quarter of a degree too high.

It is curious to notice that in the case of Buseima (p. 332) the

discrepancy of 13′ 31″ between Rohlfs’s latitude and that

estimated from Hassanein Bey’s recent work is of the same order and

of the same sign as that found at Boema; and that a negative correction

equal in amount to the sun’s semidiameter would in each case bring

the results of the two observers into fairly close agreement. The

explanation hence suggests itself that Stecker may have determined

his latitudes by observation of the upper limb of the sun at noon,

and both at Buseima and Boema failed to correct the measured altitude

for the semidiameter, thus making both latitudes 16′ too great. A

mistake of this kind, as every scientific traveler knows, is very

easily made in hurried reductions in the field; and at the time when

Stecker carried out his observations and calculations in Kufra, both

he and his brave leader were in imminent peril of losing their lives

at the hands of treacherous Badawi.

A similar explanation may account to a large extent for the

discrepancies of longitude at the two places. Thus, according to

Hassanein Bey’s work, Rohlfs’s longitude for his camp at Buseima

is 9′ too far east, and that for his camp at Boema 12′ too far

west. We have only to assume that Stecker observed the sun’s lower

limb in the morning at Buseima, and the upper limb in the afternoon

at Boema, for finding the local times, and in each case omitted to

correct the observed altitude for semidiameter, to account pretty

completely for both discrepancies of longitude.

The puzzling thing about the above explanation of the errors

of Rohlfs’s map is that Rohlfs actually traveled the distance

between Buseima and Boema, and estimated it at 120 km.,[7] whereas

Hassanein Bey’s positions would indicate that the true distance

is 40 km. greater. But as Rohlfs’s statement of the distance was

obviously written after Stecker had determined the positions of

the places astronomically, it is probable that he obtained his 120

km. by calculation from the astronomical positions, rejecting any

rough estimate he may have made of the distance from his times of

marching. Both Hassanein Bey and Mrs. Forbes had considered that the

true distance was much greater than 120 km. when they traversed it

in 1921; but as on that occasion no observations for position were

taken, it remained uncertain whether either Buseima or Boema had been

wrongly placed on Rohlfs’s map. It is now practically certain that

both were wrong.

As regards the level of Kufra, it is satisfactory to notice a very

close agreement of Hassanein Bey’s observations with those of

Rohlfs. Hassanein Bey’s barometer-readings at Ezeila, to the south

of Jof, give 389 meters for the level of that place, and he estimates

that Boema lies some ten meters higher; this would give about four

hundred meters for the altitude of Boema, a figure identical with that

found by Rohlfs. Taj, which has been built on the cliff north of Jof,

since Rohlfs’s day, is found to be 475 meters above sea-level from

a series of aneroid-readings extending over a fortnight. The outlying

villages of Kufra which lie north of Taj are lower than Taj itself, but

substantially higher than the southern villages of Kufra; Awadel is 434

meters above sea, and Hawari and Hawawiri are about the same altitude.

There is also fairly close agreement as to the extent of Kufra from

north to south. Rohlfs’s map makes the extent in altitude between

Hawawiri and Tollab to be about 35 km., while Hassanein Bey makes

it 30 km. But when we come to the distance over which the villages

extend from east to west, there is a much graver discrepancy. Rohlfs

makes the extent from east to west (Buma to Tollab) about 40 km.,

while according to the latest estimations by Hassanein Bey the true

extent is only about 21 km. As Rohlfs appears to have located many

of the villages on his map merely from Arab statements, and not from

careful personal estimation as did Hassanein Bey, we need have no

hesitation in accepting the latter’s relative positions as by far

the more nearly correct, and hence concluding that Rohlfs’s map

gives an east and west extension which is nearly double the truth.

The error in east and west extension (so far as concerns the placing

of the villages, not the extent of the vegetation) is even greater

on the map prepared by me and published by Mrs. Forbes in 1921.[8]

This is due to the distance between Jof and Tollab having been much

overestimated on the former journey; it was given to me as about 42

km., while according to Hassanein Bey’s latest estimation it is

only 20 km.

A matter which will at once strike the eye of any one who compares

Hassanein Bey’s latest map of the Kufra villages with that

published by Mrs. Forbes is that in the later map a place called

Ezeila is shown south of Jof, while in the earlier map (which was

prepared from Hassanein Bey’s own data and rough sketches) Ezeila

is shown north of Hawawiri. The explanation is that there are _two_

Ezeilas. The name “Ezeila” is applied locally to any outlying well

(usually with a clump of palms) which forms the last watering place

for caravans leaving the oasis. Thus the northern Ezeila is the last

well for a traveler leaving Kufra to go northeastward toward Jaghbub,

while the southern Ezeila is the last well in Kufra for any one going

south toward Wadai.

From the southern Ezeila of Kufra to Arkenu is 266 km. in a nearly

southeasterly direction, and there is no water or grazing on the

way. From Arkenu to Ouenat is a further 42 km. in a slightly more

southerly direction.

=The Oases of Arkenu and Ouenat.=—One of the most interesting and

important results of Hassanein Bey’s expedition is the confirmation

of the real existence of the oases of Arkenu and Ouenat, and a

fairly exact determination of their positions and altitudes. There

has long been a tradition that two oases existed in or near the

southwestern corner of Egypt. Thus the map of Africa on a scale of

1:4,000,000 published by Justus Perthes of Gotha in 1892 shows an

unnamed small oasis and well in Lat. 21° 51′, Long. 23° 3′,

and another “uninhabited oasis,” also unnamed, about 48 km. due

east of it in Lat. 21° 50′, Long. 23° 29′. Both these oases were

doubtless placed on the map from vague Arab statements; they appear

not to have been previously visited by any explorer, and indeed their

very existence was so doubtful that they have not been shown on the

maps either of the English or of the French General Staff.

I have not been able to trace any published reference to the existence

of Arkenu, but that of Ouenat has been mentioned in recent papers by

Mr. Harding King and Lieutenant-Colonel Tilho. In Mr. Harding King’s

paper of 1913[9] on “The Libyan Desert from Native Information,”

he states that he heard of a place called “Owana” or “Owanat,”

about half-way along a road from Merga to Kufra, where there is a well

and green grass after rain. The map appended to his paper shows that

Mr. Harding King’s estimate of its probable position was Lat. 21°

37′, Long. 24° 45′, which differs by nearly 130 km. from the

nearer of the two oases shown on the above-mentioned German map.

Lieutenant-Colonel Tilho, who carried out exploratory work in Tibesti,

Erdi, Borkou and Ennedi in 1912-17, mentions[10] “the still unknown

massif of El Aouinat, situated approximately between the 22nd and 23rd

degrees of latitude north and the 24th and 25th degrees of longitude

east,” and a route he heard of from Aouinat to Merga.

Hassanein Bey’s observations give for the positions and altitude

of his camps at Arkenu and Ouenat:

_Lat. N._ _Long. E._ _Meters

above sea_

° ′ ″ ° ′ ″

Arkenu 22 12 32 24 44 15 598

Ouenat 21 52 29 24 54 16 616

Thus Ouenat is only some 34 km. from where Mr. Harding King guessed

its position to be from his guide’s statements, but it is outside

the somewhat wide limits of latitude indicated by Lieutenant-Colonel

Tilho, and is nearly 150 km. from the place marked “uninhabited

oasis” on the German map; while Arkenu, which is presumably the

small oasis marked to the west of the “uninhabited oasis,” is

now proved to be some 180 km. from where it is shown on that map.

It may be remarked that Arkenu is well within the boundaries of

Egypt, while Ouenat is a short distance over the boundary, in the

Anglo-Egyptian Sudan.

The principal interest in these places lies in the possibilities

they open up for further exploration of the southwest corner of

Egypt, which has hitherto been inaccessible to military patrols,

and even to the boldest of explorers, by reason of the absence of

any certain knowledge as to the existence and position of permanent

water-supplies. Now that Arkenu and Ouenat are exactly located,

with the existence of drinkable water in reasonable quantities, it

may be possible for a traveler from Egypt to reach them and procure

the necessary water-supplies for his return journey. I say it _may_

be possible, for there are still great difficulties about access to

Arkenu and Ouenat from Egypt, although both the compilers of the German

map and Mr. Harding King were informed that an old track to Egypt runs

from Ouenat. According to Mr. Harding King’s informant, the track

runs to Dakhla Oasis, which is a distance of some 600 km. through

a waterless desert, and consequently the journey between the two

places is a very formidable undertaking for camels, even in winter;

while the suitability of the ground for motor-cars, especially in

the mountainous region round the oases themselves, is as yet unknown.

An interesting feature of Arkenu and Ouenat is that they are not

depressions with underground water-supplies, like all the other

oases of the Western Desert of Egypt, but mountainous areas where

the water is dependent on local rainfall and collected in natural

basins in the rocks.[11] The Nile Valley in the same latitudes has

practically no rainfall, but here, some 700 km. westward into the

Sahara, there is sufficient rain to maintain perennial though limited

supplies—at Ouenat even sufficient for the needs of a settlement of

some one hundred and fifty Badawi—and at certain seasons to provide

grazing for animals in the valleys and lowlands. The ground-level

in this region is high (six hundred meters above sea-level), but

the mountains near the oases rise to heights of over eleven hundred

meters above the sea, and it can hardly be doubted that the rainfall

is connected with the orography, the mountains attracting or helping

to form clouds. In this connection it is worth noting that in the

more open country further south, as well as in that to the north, the

absence of vegetation shows that rainfall is evidently much scarcer

than in the mountains around the oases; also that Ouenat, where the

mountains are higher than at Arkenu, possesses better and more abundant

water. The conservation of the water through the dry season is partly

conditioned by the almost impermeable nature of the crystalline rocks

composing the mountains, and partly by the sheltered position of the

pools in the rocky gullies, which diminishes evaporation.

The full extent of the mountains of Arkenu and Ouenat is not yet known,

but they cover at least 1000 square km. Hassanein Bey’s main route

lay along the western feet of the masses, so that their western limit

is ascertained, as also their north and south extension; but their

eastern limits in Egypt are unknown, and it is not yet certain whether

there may be a continuous chain of hills connecting the two masses to

the east. Hassanein Bey made a round reconnaissance extending some 40

km. eastward of his camp at Ouenat, without reaching the limits of the

mass. The mountains are visible from great distances from the north

and south, Arkenu having been sighted from at least 60 km. north,

and Ouenat remained visible for at least the same distance on the

track southward from it. There is a possibility that the mountains

may be less conspicuous to a traveler approaching from the east,

owing to their breaking up into smaller hills and the ground on that

side of them being higher and falling away gradually toward the Nile;

but this must remain uncertain until further exploration is undertaken.

From Ouenat to Erdi “Well” is a journey of 439 km. in a

south-southwesterly direction, the first 284 km. being in the

Anglo-Egyptian Sudan, the remaining 146 in French Equatorial

Africa. There is no water in all this stretch, but patches of dried

grass were met with at intervals in the latter half of the journey,

and some 25 km. before reaching Erdi the valleys were full of green

grass. Thus the northern limit of the equatorial rain-belt hereabouts

is approximately in Lat. 18° 50′.

=Erdi.=—Erdi appears to be the name given to an extensive tract

of country stretching between the twenty-first and twenty-fourth

meridians of east longitude, rising gradually southward and ending

in a broken east and west escarpment in about Lat. 18° 30′. The

water-source visited by Hassanein Bey, called by the guide “Erdi

Well,” is in Lat. 18° 31′, Long. 23° 10′, and is 958 meters

above sea-level. It is not really a well, but a rock-pool, similar

to those of Arkenu and Ouenat; the water is good.

Hassanein Bey’s “Erdi Well” is close to the locality marked

“Erdi-ma” on Lieutenant-Colonel Tilho’s map of 1920, but

it appears not to be the same water-source as the one visited by

that traveler. Erdi Well is at the head of a small valley draining

northward, and one has to ascend the hills to a height of 1020 meters

above sea and cross a stretch of broken plateau before reaching

the southward drainages which cut back into the scarp. Over this

broken plateau Hassanein Bey proceeded in a southeasterly direction,

descending the scarp in Lat. 18° 25′, Long. 23° 20′. The level

at the foot of the scarp was 790 meters, so that the scarp hereabouts

is some 230 meters in height.

After descending the Erdi scarp, Hassanein Bey’s track southward

across the great sandy depression which separates the Erdi plateau from

that of Ennedi, to Agah (88 km. from his camp north of Erdi Well),

appears to have been almost parallel to, and some 20 km. east of,

that followed by Lieutenant-Colonel Tilho in 1914.

=Agah.=—The water-source of Agah is a rock-pool similar to that at

Erdi; but the water is bad, owing to fouling by animals. The pool is

some 6 km. up a valley cutting back northward into the scarp which

faces that of Erdi. The position found for the pool at Agah lies

some 24 km. from the “Aga Spring” shown on Lieutenant-Colonel

Tilho’s map. There are possibly several springs and pools among the

hills in this neighborhood, all bearing the same name, which would

explain the apparent discrepancy.

From Agah the track to Enebah (65 km.) runs in a rather zigzag course

with a general southward trend. For the first 10 km. beyond the pool,

the track ascends the valley; then, mounting rapidly, it soon reaches

altitudes of over a thousand meters on the plateau.

=Enebah.=—Here is a small settlement of Badawi and a well

of good water about 28 km. east of the wells of Keita shown on

Lieutenant-Colonel Tilho’s map, on the same high plateau.

From Enebah to Bao is 120 km., by a rather zigzag track in a general

south-southwesterly direction over an undulating and hilly plateau. The

greatest altitude recorded by Hassanein Bey during his entire journey,

1184 meters above sea, was reached at a point on the road about 18

km. from Enebah. This altitude (3884 feet) is slightly higher than that

(3600 feet) which Lieutenant-Colonel Tilho records as his maximum

on the same (Erdebe) plateau at a point further west; so that the

plateau probably increases in height to the eastward. The Kaptarko

valley was crossed about 47 km. further on, and it is interesting to

note that Hassanein Bey’s data give a position for this which is

very close to the “Kapterko” of Lieutenant-Colonel Tilho’s map.

=Bao.=—Hassanein Bey’s Bao is not the “Bo” visited by

Lieutenant-Colonel Tilho, which lies over 100 km. further north, but

the place called “Orobo” on Tilho’s map and “Bao” on the

map of Wadai and Darfur which was attached to the convention between

the British and French Governments at Paris in 1919; this is evident

from the following comparison of Hassanein Bey’s position with

those scaled for the above-mentioned places from the maps referred to:

_Lat. N._ _Long. E._

° ′ ″ ° ′ ″

Bao (Hassanein Bey) 16 28 24 23 1 47

Orobo (Tilho) 16 30 0 22 59 0

Bao (convention map) 16 28 0 23 4 0

The wells of Bao are at the head of a small valley draining northward,

in which shrubs and trees are plentiful. There are several wells,

with perennial supplies, though the water becomes scarce in the dry

season and the wells have then to be deepened.

From Bao to Furawia is 145 km. in a south-southeasterly direction,

over ground partly covered with grass and small trees. About 55

km. before reaching Furawia, Hassanein Bey passed close to a hill

called Tameira, on which is a sign-post, formed of a dead tree,

marking the boundary between French and Anglo-Egyptian territory. No

astronomical observations were taken here, but Hassanein Bey’s

adjusted traverse-data indicate the approximate position of the

hill to be Lat. 15° 48′ N., Long. 23° 27′ E. The Wadai Hawar

(“Howa” of the Anglo-French convention map) was crossed about 7

km. beyond Tameira Hill.

=Conclusion.=—In concluding this analysis of Hassanein Bey’s

results, the reduction of which has occupied a large part of my

time for over two months, I may be permitted to remark that his

expedition appears to me to be an almost unique achievement in the

annals of geographical exploration. The journey of 3345 km. from

Sollum to El Obeid, most of it through inhospitable deserts sparsely

inhabited by fanatical and predatory tribes, is one which, without

a strong military escort, could have been undertaken only by a

Moslem, and by one of remarkable grit, tact, and perseverance. But

Hassanein Bey has not only accomplished this difficult journey and

brought back interesting descriptions and photographs of the country

through which he passed. Before setting out from Cairo he had applied

himself strenuously for several weeks to acquiring facility in the

use of the theodolite, and instruction in the particular methods of

reconnaissance-survey best adapted for exploration of the kind on which

he was to embark; and throughout his travels he made excellent use

of the surveying knowledge thus acquired. How complete and accurate

were his observations will be obvious from the foregoing analysis;

and the really remarkable thing is that he managed somehow to carry out

all this observation single-handed, and to maintain the continuity and

accuracy of his measurements and records over the distance of more than

2000 km. which separates the points on his route whose positions were

previously known. Thanks to the detailed and systematic character of

his observations, their reduction has been a pleasant labor, and it

has been comparatively easy to map his route and the newly discovered

places along it with a high degree of accuracy.

The principal additions to our knowledge of northeastern Africa which

have resulted from the expedition are:

(1) The true positions of Zieghen and Kufra, resulting in changes

of about 100 and 40 kms. respectively from the positions hitherto

assigned to these places on maps of Africa.

(2) The discovery of the oases of Arkenu and Ouenat, previously

unknown, and the determination of their positions and approximate

extent, thus opening up possibilities of new desert travel from Egypt

into regions of the Libyan Desert still unexplored.

(3) The discovery of a route from southwestern Egypt across the

Erdi and Ennedi plateaux of French Equatorial Africa into Darfur,

and the positions of the water-sources along it. Incidentally, this

establishes a connection with, and extension of, Lieutenant-Colonel

Tilho’s recent brilliant explorations in the French Sudan.

(4) The determination of careful barometric levels along the entire

route, affording valuable information on the orography of a vast region

of which little was previously known, and confirming Lieutenant-Colonel

Tilho’s conclusion that there is no possible drainage-outlet from

Lake Chad in an easterly direction.

[Footnote 1: Since the above was written, I have received information

from the director of Sudan surveys that a recent extension of the

Sudan triangulation-net includes Gebel Furawia as one of the points,

and that the precise position found for the summit of the hill is

Lat. 15° 20′ 59.9″ N., Long. 23° 36′ 48.1″ E., altitude

954 meters above sea-level. This position differs by about 2 km. from

that shown on the map above referred to; but in view of the fact that

the distance and bearing of Hassanein Bey’s camp from the hill is

unknown, though his observed latitude shows his camp to have been on

a parallel about a kilometer and a half north of the hill, I have

not thought it worth while to make any change in the adjustment of

Hassanein Bey’s data. The longitude adopted for the camp (p. 320)

may be slightly in error, but it is unlikely that the error can exceed

a mile or so. The difference of level between the top of the hill

and Hassanein Bey’s camp being unknown, the triangulation-level

affords no control over Hassanein Bey’s barometric value for the

latter place, and consequently I have judged it best to use El Fasher

as the south control point in adjusting the level-determinations.]

[Footnote 2: No observations are known to have been taken at

Jedabia. The position given is that which I adopted for it in

preparing a former map in 1921, and was arrived at by estimation

from a car-and-compass traverse carried out by Captain Williams from

Zuetina in 1918.]

[Footnote 3: See foot-note, p. 316.]

[Footnote 4: Rohlfs, “Kufra,” 1881, p. 226.]

[Footnote 5: “Mitt. Afrik. Ges.,” Band ii., 1880-81, p. 17.]

[Footnote 6: “Mitt. Afrik. Ges.,” Band ii., 1880-81, p. 25.]

[Footnote 7: “Mitt. Afrik. Ges.,” Band ii., 1880-81, p. 23.]

[Footnote 8: “Geographical Journal,” Vol. 68 (1921), p. 248.]

[Footnote 9: “Geographical Journal,” Vol. 42 (1913), p. 282.]

[Footnote 10: “Geographical Journal,” Vol. 46 (1920), p. 98.]

[Footnote 11: Though rare in the Western Desert of Egypt, these

rock-basins are common in the mountains of the Eastern Desert near the

Red Sea, where they are called _galts_. See my “Geography and Geology

of South-Eastern Egypt” (1912), p. 240. They are also abundant in the

Erdi and Ennedi regions of French Equatorial Africa, as we know from

the explorations of both Lieutenant-Colonel Tilho and Hassanein Bey.]

APPENDIX II

CONCLUSIONS DERIVED FROM THE GEOLOGICAL DATA COLLECTED BY HASSANEIN

BEY DURING HIS KUFRA-OUENAT EXPEDITION

W. F. Hume, D.SC., Director, Geological Survey of Egypt

BEFORE dealing with the facts ascertained I would desire to

congratulate Hassanein Bey on the successful accomplishment of an

expedition which has given us knowledge of a large tract of country

hitherto unknown to geographical science. Those of us who have

a slight acquaintance with desert travel will appreciate the fact

that he should have covered 3500 km. over an almost waterless waste

in a region which from religious or political causes is practically

closed to a European explorer. It has often meant weariness of body

and anxiety of mind, though no doubt he has been compensated by the

freedom of feeling engendered by free wind-swept spaciousness and by

the constant interest of new discovery.

Hassanein Bey has shown a keen desire to obtain data which would be

of scientific value, and consequently has collected specimens and

taken photographs which might enable those familiar with the desert

geology in Egypt to arrive at conclusions as to the geological nature

of the country traversed. Mr. Moon has examined these specimens in

my absence, and his notes and conclusions are attached.

The following points are those which have struck me most forcibly in

looking over the specimens and photographs brought back by Hassanein

Bay:

(1) Between Siwa and Jaghbub large specimens of petrified trees

were noted and photographed. This is of interest as showing the

wide extension to the west of the so-called “petrified forests.”

It emphasizes the desirability of extending the examination of the

southern edge of the Cyrenaic scarp to the western boundary of Egyptian

territory, including the portion now marked “unexplored” on the

1:1,000,000 geological map of Egypt.

(2) The beautiful specimens of the Miocene oysters _Ostrea Virleti_

and _Ostrea digitalina_ indicate clearly that Jaghbub is on the same

formation as that of Siwa, viz., Middle Miocene, while the further

continuation of these strata toward Jalo is indicated by Specimen

No. 3.

(3) At a point a little south of Lat. 28° N., a collection was made

of hard limestone. A very shelly piece among them may be Miocene, but

the others might well form part of the Eocene or Cretaceous members

which are so well developed on the same latitude to the east of the

Egyptian boundary. The absence of type fossils in the rocks renders

further identification impossible.

(4) Between March 20 and 24 Hassanein Bey was crossing a flat

plain. The question arises whether this might not be due to erosion

of the finer clays and sands which so often lie between the hard

Cretaceous limestone and more compact members of the Nubian Sandstone

series.

(5) Be this as it may, as indicated by Mr. Moon, the Nubian Sandstone

proper was met with in typical form a little north of El Harrash

(Zieghen). The specimens obtained from this point onward to the

junction with the igneous rocks about 30 km. north of Arkenu are all

varied members of the same sandstone formation which in Egypt proper

and the Sudan spreads over enormous areas.

(6) Great interest attaches to the discovery of typical granite

in the oases of Ouenat and Arkenu. The main rock is of pegmatitic

type, being composed of well-shaped felspars, glassy quartz, and

hornblende. A point brought out by the photograph is the intense

action of temperature variation on these igneous rocks. The whole

of the hillside is strewn with gigantic boulders, some of which have

been split into large pieces which obviously once formed part of the

same block.

As regards the nature of the relations between the granite and the

Nubian Sandstone, it is to be noted that the granite difference of

level might be explained (a) by the existence of a fold, (b) by the

presence of a fracture line or fault, (c) by intrusion of the granite

when in a molten condition into the overlying sandstone.

After conversation with Hassanein Bey, and a closer examination of

his photographs from this point of view, one is led to the following

conclusion:

(1) A fold seems possible, because the sandstone (which dips or

slopes off the granite in certain folds in the south of Kharga Oasis)

is seen to be obviously dipping toward the spectator in the cinema

photograph of camels coming through the valley of Ouenat. Taking

(c) first, we have no proof anywhere in Egypt that granite has been

intruded into the Nubian Sandstone, in all cases where the relations

are clearly displayed the granite having obviously been worn down

before the sandstone was deposited on it.

(2) We are consequently disposed to adopt the view, pending further

study, that the differences of level may be due to the existence of

a fold. The alternative would be the presence of a fracture line,

along which the granite has been pushed up in a solid form to a higher

level than the sandstone which normally overlies it, or the sandstone

has been led down along the line of weakness against the granite.

A very interesting feature is the presence of well-made drawings of

giraffes and ostriches on the granite boulders. As Hassanein Bey points

out, the camel is absent, and it is to be regretted that there are

no pictures of human beings. These _graffiti_ may be of ancient date,

being drawn at a period when rainfall was greater in this portion of

North Africa than it is at present.

Hassanein Bey’s expedition has thus indicated that both the Miocene

strata in the north and the great Nubian Sandstone formation further

south continue well to the west of the western Egyptian boundary with

unchanged characteristics, while the discovery of the granitic oasis,

as I understand within the boundaries of Egyptian territory, opens

up the possibility of developing alternative routes to Darfur from

Dakhla Oasis, and also indicates a water-base of great importance in

connection with the exploration of the unknown territory lying west

of the route followed by Hassanein Bey. Its further study from the

geological standpoint would be of great interest.

APPENDIX III

NOTES ON THE GEOLOGY OF HASSANEIN BEY’S EXPEDITION, SOLLUM-DARFUR,

1923

F. W. Moon

HAVING been requested by Hassanein Bey, in the absence of Dr. Hume,

to report upon the interesting geological specimens collected by him

on his recent exploratory tour through the Western Desert from Sollum,

on the southern shores of the Mediterranean Sea, to Darfur in the

Sudan, I have much pleasure in submitting the following short summary

of the main features of the journey from a geological point of view,

as deduced from the specimens collected.

Although the specimens are small and, in the case of the igneous

rocks, much weathered, yet for all intents and purposes they are

quite sufficient to enable one to make deductions and conclusions as

to the main geological formations passed over.

As the explorer explains, there was not the freedom of transport

he would have desired for making a larger collection of full-sized

specimens, nor did he wish to incur the displeasure of those who

formed his escort by seeming to do anything that might appear in any

way suspicious, such as the constant breaking and collecting of stones.

From the tabulated list of specimens herewith appended, it may

be seen that the beginning of the journey was made over Miocene

formations indicated by fossil oysters and pectens (identified as

_Ostrea digitalina_, _O. Virleti_, _Chlamys zitteli_, and others),

of which there are seven valves of the former, two of the second,

two of the third, and five which resemble _Chlamys sub-malvinæ_.

The Miocene formations continue through Siwa, Jaghbub, and Jalo,

and far southward to a point about 180 km. to the south of Jalo (see

Specimens 1-4), where the last Miocene specimen (No. 4) was picked up.

At this point begins a wide barren stretch of flat and desolate

country, devoid of rocks of any particular geological interest

beyond the thin covering of “sand and alluvium” which extends for

nearly 200 km. (four days of monotonous marching) along the route to

the south.

Then, when about 50 km. north of Zieghen, the explorer noticed that

the aspect of the country took a sudden change; the light yellow of

the Miocene limestones and desert sands gave place to brighter, more

varied, and highly colored scenery, which the specimens show was due

to the approach of the Lower Cretaceous Nubian Sandstones, which,

wherever they occur, add beauty to the landscape in unbelievable

brilliancy and variety of coloring.

Although greens and blues are sometimes observed, red is the dominant

color, all shades of pink, terra-cotta, maroon, and brick red are

blended together, and umbers and ochers are sometimes present.

Thus we are provided with a point well westward of any hitherto known

on the northern limits of the Nubian Sandstone; in other words, the

evidence suggests the continuation westward by some 600 km. of the

Nubian boundary shown on the existing 1:1,000,000 colored geological

map of Egypt (1910).

Mention may here be made of the apparent absence of specimens

definitely representing the younger Cretaceous rocks which are shown

colored green, on the map just referred to, to the east; but this

may be readily accounted for by the presence of the expansive plain

passed over between Jalo and Zieghen, the “sand and alluvium”

covering of which is quite sufficient to hide all evidence of the

younger rocks of that age.

Another question rendered obscure by the presence of this large

flat expanse of “sand and alluvium” is the exact position of the

southern limits of Miocene formations. If we assume (which seems to

be the case) that the point, 180 km. to the south of Jalo, where the

last Miocene specimens were collected, be the southern boundary of

the Miocene, then we find that the distribution of that formation as

now suggested is of particular interest as (1) indicating a western

extension of the general outline of the ancient Mediterranean Ocean in

Miocene time; and (2) adding extra weight to our conceptions as regard

the period (in geological chronology) of the Egyptian-Sinai uplift

which caused the elevation of land involving a considerable portion of

Egypt in pre-Miocene times, and ultimately defining the shores of the

Miocene Sea more or less as we now follow it from this newly discovered

spot between El Harrash (Zieghen) and Jalo to a short distance east

of Siwa from where it runs northeastward to the thirtieth degree of

latitude, along which it continues with little variation to Suez.

It would appear that all Egypt lying between the Miocene Gulf of Suez

in the east and the Siwa-Zieghen Miocene shore-line in the west and

southward was dry land in Miocene times, and therefore exposed to

denudation extending over a vast geological period during which the

Nubian Sandstone and younger Cretaceous rocks were laid bare and in

a position to have Miocene strata laid down upon or against them.

The Nubian Sandstone, as indicated by the Specimens 5-10, shows

identical characteristics to those exhibited wherever it occurs in

Egypt or Sinai. It is a sandstone consisting in the main of more or

less fine rounded grains of pure quartz, through which are distributed,

in greater or lesser proportions, larger grains or pebbles. In cases

where the latter predominate, a pudding-stone or conglomerate results;

where the larger grains are sparsely distributed, a porphyritic

appearance is suggested.

The cementing material, which may be either calcareous, silicious,

or ferruginous, is the color-imparting medium, the depth of color

depending upon the amount and composition of iron oxides present in

it, and when this material is weathered, washed out, and accumulated

into pockets it becomes, when finely ground, suitably adapted for

the manufacture of paints.

The Nubian Sandstone continues south of the Miocene-Nubian boundary

above referred to, to a point some 15 km. north of the Arkenu

Mountains.

Approaching this point, still another change in the general aspect

of the country met the eye of the explorer: the brighter coloring of

the sandstones gave place to the duller browns, grays, and blacks of

an abrupt range of igneous hills, the position on the ground where the

igneous rocks come up through the Nubian Sandstones being approximately

25 km. north of Arkenu.

The changes of scenery in passing from one formation to another are

strikingly seen in the excellent collection of photographs procured

by Hassanein Bey, who is to be highly complimented on the success he

obtained under great difficulties and inconveniences.

Judging from the Specimens 11-12 submitted for examination, the igneous

rocks, of which the Arkenu-Ouenat Hills are composed, consist mainly

of coarsely crystalline granites and syenites varying in texture and

appearance, and through them run intrusive veins of finer-grained

dike rocks.

The Arkenu Hills are mostly composed of rocks represented by Specimens

12 and 14, which are really somewhat similar in composition.

No. 12 consists of a holocrystalline aggregate of large crystals

of a light gray (possibly a decomposed or kaolinized orthoclase)

alkali-felspar, which constitutes the main bulk of the rock. No quartz

is visible in the hand specimen, which is greatly weathered, and only

gives a specific gravity of a little over 2.5. Small crystals of dark

greenish hornblende are well formed, and occur in fewer numbers than

in Specimens 17 and 21, which are representatives of the rockmass of

the Ouenat Hills to be described presently.

Specimen 14 is an unweathered gray rock chiefly composed of a mottled

gray alkali-felspar, with hornblende crystals in similar numbers to

those in Specimen 12.

The microscopic examination of a rock-section made from Specimen 14

corroborates the above description, but introduces the possibility of

the presence of nephelin in granular-like patches in the slide, which

correspond to darker slightly lustrous areas in the hard specimen;

however, no nephelin has been actually identified.

Specimens Nos. 12 and 14 may therefore be called syenites.

Running through the syenites of the Arkenu Hills are veins of intrusive

rocks represented by Specimens Nos. 11, 13, and 15, and no doubt many

others occur.

Specimen No. 11 represents a vein of a hemicrystalline, hard dark

green rock weathering brown on the outer surface, with innumerable

small dark specks which are scarcely discernible in the unweathered

portion of the specimen.

Under the microscope this rock is found to be of considerable

interest. It consists of an aggregate of small phenocrysts of

idiomorphic felspar, which in places assumes the appearance of a

crypto- or microcrystalline felspathic matrix crowded with acicular

crystals of a green mineral resembling ægirine. The latter are in

places irregularly distributed, but in areas where the felspar occurs

in roughly rectangular or lozenge form, the ægirine microlites are

crowded round the edges of the latter.

No quartz is noticeable in the rock-slide, and the rock may be

tentatively determined as an ægirine-felsite, apparently similar to a

rock described and figured in Harker’s “Petrology for Students.”

A second vein in the Arkenu Hills is represented by Specimen No. 13,

which is a brownish quartzite.

The third vein is indicated by Specimen No. 15, which is a dark gray

laminated rock, weathering to reddish brown, very fine in texture,

with small clear crystals of phenocrysts sparsely disseminated through

the ground-mass. The rock-slide shows, under the microscope, a great

similarity to Specimen No. 11 as described above. The felspar here,

however, forms a much finer crypto-crystalline ground-mass than

in the former, and the ægirine microlites are smaller, tapering,

and not so well formed. This rock may also be tentatively called a

fine ægirine-felsite.

The Ouenat Hills are mainly composed of rocks represented by Specimens

17 and 21, the chief constituent of which is a gray alkali-felspar

(possibly orthoclase with some microcline). Quartz is well represented

in idiomorphic forms; no mica is noticeable in the hand specimens,

but many well-developed prismoidal crystals of very dark or dark

green hornblende are thickly distributed throughout the mass.

No slide was made of these specimens owing to their fragile condition

on account of weathering, but the rock may be determined as a coarsely

crystalline gray hornblende granite.

Specimen No. 18 is another representative rock from, and constitutes a

considerable bulk of, the Ouenat Hills. It may be termed a red granite,

approximating to an aplite with very little mica, which decomposes

and forms oxides of iron which have stained the rock a brownish red;

quartz and felspar form the main bulk of the rock.

As in the case of the Arkenu syenites, so here in the Ouenat granites

we find other examples of endogenous veins running through the parent

rock, represented by Specimens 16, 19, and 22.

Specimen No. 16 represents a vein of purplish felsite, in the felsitic

ground-mass of which occur phenocrysts of idiomorphic felspar.

Specimen No. 19 represents a vein of pure white granular quartz rock

which occurs in and may have been the cause (through denudation)

of the cave found in the foot-hills of the Ouenat range.

Specimen No. 22, found at Garet Shezzu, is a typical quartzite which

may also occur as a vein in the granites.

Two specimens found inside the cave in the Ouenat Oasis are of

particular interest. These specimens are Nos. 20 and 21. The

former, a laminated travertine, could only have been deposited

from running water, as the formation of ripple-markings confirms;

and from notes made by the explorer at the time of his inspection,

we learn that there was quite a lot of it lying about on the floor

of the cave. Under the microscope spheroidal structure is displayed,

representing the ripple-markings, and in the matrix of calcite many

fragments of quartz, felspar, etc., are conspicuous, these having been

derived from the denuding granites. No organic remains were observed.

The second specimen (No. 21) is a fragment of the hornblendic granite

of which the Ouenat Hills are chiefly composed, and which forms

the roof of the cave; this is coated on one side with a thin black

iron-manganese film, similar to the well-known deposit on the rocks

in the Nile at or near the Asswan Dam.

This whole igneous area, which includes the newly discovered mountains

and oases of Arkenu and Ouenat, is possibly of limited extent, and

occurs in, and is possibly surrounded by, a much wider expanse of

Nubian Sandstone, in a similar manner to several other such areas

already shown on the 1:1,000,000 geological map of Egypt.

Judging from other known similar occurrences where igneous rocks

appear surrounded by Nubian Sandstones, we may infer that the latter

were deposited upon the ancient igneous rocks which subsequently rose

vertically, bending the superincumbent strata over and round them,

possibly only to a slight degree in this instance, as none of the

photographs show very highly dipping rocks.

On leaving Ouenat for Erdi the igneous area is soon left behind. The

actual junction between it and the Nubian Sandstone (which again forms

the surface rock) occurs at a point about 20 km. south of Ouenat, and

the aspect of the country again changes from the more uneven weathering

of the igneous range of grays and browns to brilliant colorings of the

Nubian Sandstone which forms a long series of prominent escarpments

rising to heights bordering on 1000 meters above the sea between

Enebah and Kuttum, after which the ground begins to fall, until El

Fasher is reached, where the ground-level is only about 700 or 800

meters in height.

=Summary.=—The several interesting geological features suggested

by the recent expedition may be summarized as follows:

1. That Miocene rocks extend southward, to or near the twenty-seventh

degree of north latitude, forming a large bay bordered by older rocks.

2. That the Miocene rocks, resting here apparently upon or against

Nubian Sandstones, seem to follow the same conditions noticed first by

Dr. Hume in the Gulf of Suez region, namely, that they rest upon older

and older formations the further southward they are found; in other

words, that prior to the deposition of the Miocene there was a time

of denudation which was more effectual in the south than in the north,

owing to the fact that in the south was an area of greater uplift.

3. That a large area of Nubian Sandstone (Cretaceous) exists south

of this latitude.

4. That a newly discovered range of igneous rocks in the Arkenu Hills

exists well inside Egyptian territory, and possibly entirely within

this Nubian Sandstone area, or connected as a tongue to a larger

igneous massif lying in the south.

5. That the Cretaceous rocks (younger than the Nubian Sandstone)

which appear on the colored Geological Map of Egypt further to the

northeast, possibly do not occur along the route traversed, having

been concealed beneath “sand and alluvium” areas.

LIST OF SPECIMENS COLLECTED BY AHMED MOHAMMED HASSANEIN BEY IN HIS

EXPEDITION FROM SOLLUM TO DARFUR

_No._ _Date_ _Locality (As taken from _Determination of

1923 descriptions on labels)_ Specimens_

1 — Siwa Three crystal fragments

of selenite; one pecten

and two oyster shells

(possibly of Miocene age)

2 — Jaghbub One pecten in a shelly

limestone (possibly

indicating Miocene age)

3 — Surface rocks on the way One piece of fossilized

from Jaghbub to Jalo wood; three loose

silicious pebbles; two

long concretions of

calcareous grit, and

fibrous salt crystal

(curved, five inches long)

4 March In Wadai, in small Two loose pebbles of

20 patches calcareous grit with

quartz grains

5 March Getting near El Harrash Nubian Sandstone

24 (Zieghen), patches of (one specimen)

this strewn (broken)

before reaching Halab

6 March One day’s journey from Hard ferruginous bands

28 El Harrash (Zieghen), on from Nubian Sandstone

way to Kufra (five specimens)

7 March Garet El Sherif Nubian Sandstone

29 (three specimens)

8 — Gebel El Neri, _garas_ Ferruginous bands

nearing Hawari (color maroon) from

Nubian Sandstone (three

specimens); one black

ferruginous “bomb”

9 — Kufra (Taj) hills Blocks of Nubian

Sandstone (three

specimens)

10 April Between Kufra and Nubian Sandstone

22 Ouenat; specimens from (one specimen);

chain of hills crossed and ferruginous

that day bands from Nubian

Sandstone (two

specimens)

11 April Arkenu Mountain Igneous rock

24 (ægirine felsite)

12 April From patches of Arkenu “ (badly weathered

24 Mountain; there are big syenite)

hills formed entirely of

it . . . on the outside

of the mountain

13 April From big patches north “ (quartzite vein in)

24 of Arkenu Mountain

14 April From Arkenu Mountain “ (gray syenite)

25 itself

15 April Found in big blocks “ (ægirine felsite)

25 buried in the ground on

the border of Arkenu

Mountain, in the Arkenu

valley

16 — Specimen from formations “ (felsite)

(in layers) found in

Ouenat big valley

17 — Ouenat Mountain is “ (badly weathered

mostly of this stone hornblende-granite

18 — Stone of which Ouenat is “ (badly weathered

generally formed granite)

19 — Found inside the “ (quartz vein)

water-cave at Ouenat,

near the water-level;

plenty of it in small

patches

20 — Found inside the Calcareous deposit from

water-cave at Ouenat running water (travertine)

21 — Found inside the Igneous rock

water-cave at Ouenat, in (badly weathered

the roof; most of the hornblende-granite,

stone of the cave and coated with polished

mountain is of this kind film of iron which may

have come from the water)

22 May 8 From Garet Shezzu, near “ (fine quartzite)

Ouenat

23 May 10 Between Ouenat and Erdi Nubian Sandstone

(one specimen)

24 May 13 Found strewn on red Ferruginous band

sand, getting near Erdi; (containing hematite) from

nothing but red sand and Nubian Sandstone

this stone

25 May 16 Erdi Hills Dark red clay, with small

percentage of quartz sand

(grinds up into dark

brick-red powder)

26 May 16 Stone of Erdi Hills Brick-red clay, with small

percentage of quartz sand

(grinds easily into

bright, brick-red colored

powder)

27 May 19 Agah Hills Soft, fine, yellow to red,

slightly calcareous

micaceous sandstone

Transcriber's note:

pg 220 Added: ".”" after: "though your camp is far away"

pg 231 Changed: "and not the the intrinsic value" to: "and not

the intrinsic value"

pg 236 Changed: "ground near Baret Shezzu" to: "Garet"

caption of illustration facing pg 260, Changed: "WOMAN OF THE

PALLATA TRIBE" to: "FALLATA"