The geography and geology of south-eastern Egypt

by John Ball

The observed azimuths, unlike the observed latitudes, were more accurate than the results of triangulation, repetition having shown them to be reliable within 2″ or 3″, an error of which magnitude would soon be surpassed in the process of continuing a chain of azimuths with the unadjusted values of the angles of the triangles, which were the only values possible to be used in the field. On arriving at an azimuth station, therefore, a fresh chain of azimuths was begun from the results of the observation, and continued to the next station where astronomical observations were undertaken. The accumulated azimuth error was, however, never found to exceed 10″ in any chain, a quantity which could not sensibly affect the computed positions of points for plotting on the maps.

Connexion with the Sudan Surveys.—At the south end of the area, connexion was made to a number of points triangulated by the Sudan Surveys, but as the Sudan triangulation was commenced as an independent piece of work from an observed latitude and a telegraphically determined longitude, the connexion affords no check on the accuracy of the triangulations. The difference found between my positions and those of the Sudan Surveys was practically constant for all the Sudan points connected, and amounted to 3″·5 in latitude and 26″ in longitude[70]; these figures represent the errors in the assumed latitude and longitude of the starting point of the Sudan Surveys, and will be employed as corrections to the Sudan positions now that a complete chain of triangulation connects Berber with the Mediterranean.

Levels of Triangulation Points.—The altitudes above sea-level of all triangulation points were determined by vertical angular measurements carried out at the occupied stations, an actual sea-level datum being obtained by including rocks awash in the sea among the triangulated points. To secure constancy of atmospheric refraction as far as possible, vertical angles were always read in the middle of the day, where the change of refraction is slowest. For the occupied stations, refraction and curvature were eliminated by reciprocal observations. For intersected points the formula h = d tan θ + 1 − k2rd² was used, the value of d tan θ being first found by five-figure logarithms and then that of the curvature and refraction correction 1 − k2rd² by means of the very convenient “Universal” slide rule of Nessler.[71] The value of k found from a discussion of the first few reciprocal observations was found to be very nearly 0·13, corresponding with the mean of European determinations, and this value for the coefficient was employed throughout the work for intersected points.[72] For obtaining the correction 1 − k2rd² by the slide rule, a mark R was scratched at 1210[73] on the lower scale of the slide; by bringing this mark R opposite to the distance (in kilometres) on the lower scale (or, where the logarithm of the distance was more convenient, by bringing the mark vertically under that logarithm on the log scale of the rule by means of the cursor) the correction could be read off directly on the lowest fixed scale opposite the end-graduation of the slide. Usually four or five values for the altitude of a single point were obtained from a corresponding number of stations, and the mean taken; the various values generally agreed within two metres.

The constant combination of vertical angular measurements with horizontal ones was of great service from another point of view from that of providing altitude data for the maps. It frequently happened that a peak observed at one station could not be identified among a number of similar peaks visible at another station. When this trouble arose, the vertical angles offered a way out of the difficulty. Vertical and horizontal angles were read off to a number of likely-looking peaks; on working out the triangles to the nearest minute of the observed angles, the distance of each peak was obtained on the assumption that it was the one required. Then to find which of the several peaks was the correct one, the elevations were worked out, assuming the distances correct; in only one case would the level agree from the two stations, and this obviously discriminated the peak required. The working out of the triangles for this purpose could be done with sufficient accuracy in a very few minutes by means of the slide rule, and many points were thus saved from rejection consequent on misidentification.

Checks on absolute level were frequently obtained by observing depression angles to the sea horizon, using the formula θ = 107·8 √ h , where θ is in seconds of arc and h is the altitude in metres. But for high stations the horizon is so distant that very small variations in refraction cause rather large errors in the result, so that this method only furnished a rough check.

Summary of Triangulated Positions.

The following tables give the geographical positions and altitudes above sea-level of all points triangulated, arranged in order of diminishing latitude, i.e., from north to south. The list includes the points fixed within the Sudan for connexion with the Sudan Surveys. Stations occupied are indicated by an asterisk against the number of the point. It will be noticed that in some cases several different mountains bear the same name though widely distant from each other; also that where a single mountain mass possesses several peaks or summits, each of these has been fixed separately.

Summary of Triangulated Positions.

Field Number of Point.		Name.	Mark.	Latitude N.			Longitude E.			Altitude Metres.
				°	′	″	°	′	″
	21	G. Hamrat Wogud	cairn.	25	9	34	34	20	0	1,103
	29	G. Iteima	„	25	8	1	34	11	13	849
*	204	G. Igli	„	25	4	6	34	36	16	975
*	26a	G. Atut	„	25	0	56	34	23	49	908
*	203	Erf el Fahid	„	25	0	5	34	11	52	579
	14	G. Hagar Dungash	„	24	59	12	34	2	33	815
*	218	G. Sukari	„	24	56	50	34	42	50	476
	216	G. Um Tundeba	summit.	24	55	48	34	47	29	550
*	202	Muelih base	E. peg.	24	54	44	34	5	7	406
	219	Isolated hill near sea	summit.	24	54	23	34	54	21	190
*	201	Muelih base	W. peg.	24	53	37	34	4	18	398
	19	G. Muelih	cairn.	24	52	44	34	0	37	707
*	225	Kurdeman mines	„	24	52	35	34	41	35	525
	71	Marwot Rod el Ligah	„	21	51	31	34	8	21	514
	206	G. Mudergeg	summit.	24	51	0	34	22	1	885
	205	G. Hangalia	„	24	50	29	34	38	43	1,241
*	215	G. Ghadir	cairn.	24	50	9	34	47	22	636
*	32a	G. Nugrus	„	24	48	34	34	35	47	1,505
*	25	G. Migif	„	24	47	23	34	27	30	1,199
*	214	G. Allawi	„	24	46	42	34	49	39	515
	211	G. Zabara	„	24	45	21	34	41	53	1,361
	224	G. Lewewi	„	24	44	38	34	46	39	654
	212	Ridge near G. Zabara	N. end.	24	43	48	34	40	56	1,104
	221	Hill near sea	summit.	24	42	31	35	3	15	—
	208	G. Hamrat Selma	„	24	41	58	34	20	58	761
	210	Peak in G. Hafafit	cairn.	24	40	44	34	37	8	722
	240	Wadi Gemal island	N. end.	24	40	45	35	9	6	0
*	223	G. Sikait	cairn.	24	39	55	34	48	5	771
	213	G. Um Moghar	summit.	24	39	16	34	41	5	860
	24a	G. Abu Khrug	cairn.	24	38	57	34	16	19	870
	20	G. Sufra	beacon.	24	38	42	34	4	13	690
	241	Wadi Gemal island	S. end.	24	38	38	35	10	36	0
	207	G. Nahud	N. cone.	24	35	36	34	22	14	662
*	209	Peak in G. Hafafit	beacon.	24	35	32	34	45	22	744
*	222	Madaret Um Gamil	„	24	34	52	34	56	28	454
	226	G. Abu Had	summit.	24	34	12	34	36	6	633
	242	Low spur of coast	tip.	24	33	47	35	10	2	0
	235	G. Um Regeba	summit.	24	33	36	34	42	29	571
	233	G. Nahud	S. cone.	24	33	35	34	20	11	662
	239	Low spur of coast	tip.	24	28	43	35	10	58	0
	247	G. Um Suerab	summit.	24	26	50	34	42	33	1,024
	231	G. Um Sueh	„	24	26	45	34	54	30	781
	236	G. el Abiad	„	24	26	27	34	48	56	892
*	227	G. Abu Hegilig	„	24	26	16	34	58	32	607
	237	G. Um el Abbas	„	24	26	11	34	56	33	697
	232	G. Nukheira	„	24	25	58	34	32	53	876
	73	G. Um Goraf	cairn.	24	25	33	34	18	28	—
	252	G. Durunkat	centre.	24	23	43	34	45	51	924
	274	S. end of low sandy island	—	24	22	41	35	22	56	0
	255	G. Um Sedri	S. peak of twin.	24	22	0	34	41	3	970
	234	G. el Heda	summit.	24	20	56	34	30	11	862
	248	G. Sarobi (S. peak)	„	24	20	50	35	9	0	471
*	228	G. Um Heshenib	beacon.	24	20	49	34	50	53	1,135
	243	G. Hefeiri	summit.	24	20	22	35	1	21	612
	246	G. Khulla	„	24	19	43	34	38	42	978
	253	G. Tarfawi	N. end of ridge.	24	18	46	34	55	54	1,363
	251	G. Marasan	summit.	24	17	34	34	44	56	1,261
	249	G. Abu Ghusun	„	24	16	1	34	58	17	1,389
	245	G. Metawit	„	24	15	51	34	31	48	741
*	230	G. Abu Hamamid	beacon.	24	14	41	34	47	38	1,747
	250	G. Um Usher	summit.	24	14	11	34	53	21	1,487
	259	G. Um Hasidok	„	24	12	45	34	54	46	1,497
*	229	G. Hamata	beacon.	24	12	17	35	0	16	1,978
	258	G. Abarun	summit.	24	11	20	34	50	18	1,602
	257	G. Abu Argub	„	24	11	1	34	45	43	1,609
	75	G. Hamrat Mukbud	cairn.	24	9	53	34	23	17	890
	254	G. Ras el Kharit	peak.	24	9	25	35	1	55	1,661
	261	G. Khashir	summit.	24	9	14	35	4	50	1,565
	262	G. Ras el Kharit	peak.	24	9	2	35	0	28	1,564
*	256	G. Kahfa	beacon.	24	8	18	34	38	55	1,018
*	399	Hill near Bir Qoleib	beacon.	24	8	6	33	42	46	355
	400	Bir Qoleib	clay basin.	24	6	36	33	41	20	239
	287	G. el Anbat	summit.	24	5	12	34	54	58	788
	263	G. Mikbi	S. end of ridge.	24	4	54	35	4	49	1,388
	276	G. Um Huk	cairn.	24	4	41	35	15	34	517
	279	G. Um Sellim	E. peak.	24	3	52	35	9	51	947
	320	Peak N. of Berenice	summit.	24	3	41	35	26	30	276
	264	G. Egat	peak.	24	3	40	35	3	32	1,277
	273	G. Egat	summit.	24	2	52	35	2	29	1,422
	280	G. Abu Ghalqa	cairn.	24	1	7	35	16	47	561
*	260	G. Abu Gurdi	beacon.	24	0	11	35	5	17	1,562
	288	G. Derhib	summit.	24	0	8	35	1	29	1,160
*	315	Hill near Berenice	beacon.	24	0	4	35	30	37	196
	268	G. el Homur	summit.	23	58	54	34	55	16	731
	289	G. Um Gunud	cairn.	23	57	46	35	12	10	989
*	339	Limestone hill on Ras Benas	beacon.	23	57	16	35	43	10	187
	271	G. Selaia	summit.	23	57	14	34	52	13	787
*	317	Hill on Ras Benas	beacon.	23	56	40	35	39	44	193
*	316	Limestone peak, Ras Benas	„	23	56	36	35	36	9	189
*	338	Hill on Ras Benas	cairn.	23	56	1	35	40	53	197
	291	G. Aidab	summit.	23	55	52	35	13	38	848
	270	Hill near G. Selaia	„	23	55	46	34	53	58	623
*	275	Low hill near G. Selaia	beacon.	23	55	30	34	54	37	563
	278	G. Geneina	peak near N. end.	23	54	56	34	47	45	548
	336	G. Um Maiat	N. end.	23	54	45	35	13	35	928
*	313	Berenice Temple	beacon.	23	54	39	35	28	26	8
	290	Marwot Elemikan	summit.	23	54	14	35	6	8	648
	319	Peak N. of G. Kalalat	„	23	54	10	35	13	55	870
	334	Hill near Wadi Mindeit	„	23	53	57	35	22	0	—
	340	Sheikh’s tomb at Ras Benas	centre.	23	53	50	35	47	13	3
	341	Tip of Ras Benas	sandy point.	23	53	42	35	47	5	0
	266	G. Abu Derega	summit.	23	53	38	34	59	13	831
	335	G. Um Maiat	S. end.	23	53	34	35	14	48	842
	333	High range N. of G. Kalalat	N. end.	23	53	3	35	15	1	875
	77	G. el Nekeiba	cairn.	23	52	34	34	22	10	570
	330	Hill near Wadi Kalalat	summit.	23	52	29	35	22	18	328
	318	G. Um Maiat	central peak.	23	52	24	35	15	36	821
	332	High range N. of G. Kalalat	S. end.	23	51	59	35	16	29	762
	331	G. Kalalat	minor peak.	23	50	48	35	15	51	743
	294	N. end of Mukawar Island	—	23	50	47	35	48	31	0
	293	G. Batoga	central peak.	23	50	7	35	20	46	802
	329	G. Kalalat	N. peak.	23	49	57	35	17	6	1,080
	294a	S. end of Mukawar Island	—	23	49	53	35	48	19	0
	314	G. Batoga (S. peak)	beacon.	23	49	37	35	21	9	785
*	282	G. Kalalat	„	23	49	9	35	17	36	1,125
	328	G. Batoga	minor peak.	23	48	57	35	22	47	413
	353	Minor peak of G. Kalalat	S. one of pair.	23	47	37	35	18	46	894
	355	G. Um Hegilig	summit.	23	47	13	35	14	32	966
	327	G. Dibag	NW. peak.	23	46	47	35	21	23	517
	308	G. Dibag	SE. peak.	23	46	40	35	22	4	544
*	265	G. Dahanib	beacon.	23	45	44	35	11	10	1,270
*	269	G. Um Bisella	„	23	45	34	34	57	39	824
*	277	G. Zergat Naam	„	23	45	28	34	40	34	823
	345	G. Reyan	N. peak.	23	45	20	35	17	50	740
	346	G. Reyan	S. peak.	23	44	7	35	17	20	863
*	343	Hill near Shenshef ruins	beacon.	23	44	5	35	22	40	290
	292	Erf el Gemal	W. end of ridge.	23	43	37	34	52	10	673
	272	G. Hagar el Fil	summit.	23	43	5	34	42	3	845
	281	G. Shut	„	23	42	35	35	16	59	930
	398	Bir Abu Hashim	principal well.	23	41	56	34	4	26	320
*	397	Hill near Bir Abu Hashim	beacon.	23	41	44	34	3	33	386
	348	Hill near W. Salib Abiad	summit.	23	41	5	35	7	3	703
	325	G. Um Etli	central peak.	23	39	54	35	23	22	795
	384	G. Abu Husenat	summit.	23	39	45	35	1	15	725
	326	G. Um Etli	W. peak.	23	39	32	35	21	52	844
	324	G. Um Etli	E. peak.	23	39	26	35	23	53	764
	295	G. Hendusi	sharp peak.	23	39	15	34	58	44	678
	344	G. Um Akra	beacon.	23	37	58	35	16	41	1,050
*	385	Ruins of Um Eleiga	„	23	37	20	35	3	5	599
	302	Peak near G. Abu Dahr	summit.	23	37	16	35	6	44	840
*	79	Um Harba	beacon.	23	36	56	34	30	38	688
	356	G. Um Akra	S. peak.	23	36	35	35	16	58	970
	347	G. Hindia	summit.	23	36	27	35	13	39	873
	337	Zeberged Island	central peak.	23	36	16	36	11	42	238
*	267a	G. Abu Dahr	beacon.	23	36	8	35	5	46	1,131
	305	G. Abu Sieiyil	summit.	23	35	16	35	1	4	833
	321	G. Faraid	peak.	23	34	8	35	23	18	1,131
	323	G. Faraid	„	23	33	29	35	21	50	1,341
	361	Hill S. of G. Abu Dahr	summit.	23	33	28	35	4	42	912
	322	G. Faraid	highest peak.	23	33	7	35	22	10	1,366
	342	G. Faraid	„	23	31	53	35	22	46	1,068
	360	Hill S. of G. Abu Dahr	summit.	23	31	43	35	5	15	772
	362	Hill S. of G. Abu Dahr	„	23	31	37	35	2	49	793
	359	Hill S. of G. Abu Dahr	„	23	31	17	35	6	22	784
*	285	G. Faraid	peak.	23	30	53	35	20	25	1,259
*	85	G. Um Khafur	beacon.	23	29	54	34	29	19	560
	357	G. Faraid	minor peak.	23	29	35	35	17	30	862
	286	G. Faraid	“The Bodkin.”	23	28	58	35	20	35	1,232
	350	G. Faraid	outlying peak.	23	28	39	35	17	35	875
	351	G. Faraid	peak.	23	28	35	35	16	31	954
	352	Granite peak near Wadi Rahaba	summit.	23	27	48	35	13	15	697
	349	G. Faraid	outlying peak.	23	27	14	35	19	5	904
	297	G. Orga	beacon.	23	26	21	35	8	17	682
	363	Hill near Wadi Rahaba	summit.	23	26	18	35	12	38	506
*	296	G. Abraq	beacon.	23	25	19	34	46	48	667
	365	Hill near Wadi Rahaba	summit.	23	25	2	35	11	42	536
	389	G. Faraid	minor peak.	23	24	57	35	24	42	585
	358	G. Faraid	peak.	23	22	39	35	22	19	916
	395a	G. Abraq	„	23	22	26	34	50	18	699
	395	G. Abraq	„	23	22	19	34	50	4	705
*	87	G. Awamtib	beacon.	23	20	59	34	26	39	793
*	299	G. Um Tenedba	„	23	19	48	35	10	40	656
	368	Hill near G. Um Tenedba	summit.	23	18	43	35	12	36	555
*	390	Plateau near Abu Saafa	beacon.	23	18	40	34	48	30	639
	307	G. Saalek	peak E. side.	23	18	18	34	31	10	753
*	354a	G. Fereyid	beacon.	23	17	29	35	22	48	612
	394	G. Hodein	„	23	16	20	34	53	25	695
	380	G. Hodein	corner of scarp.	23	16	18	34	52	5	718
	304	Peak W. of G. Um Reit	summit.	23	15	26	34	30	14	805
	306	Peak W. of G. Um Reit	„	23	15	23	34	31	47	837
	366	Hill near Wadi Rahaba	„	23	15	4	35	16	25	420
*	300	G. Um Reit	beacon.	23	15	4	34	34	17	857
*	298a	G. Harhagit	„	23	14	35	35	12	52	542
	393	G. Tibatib	summit.	23	12	41	35	1	28	396
	387	Hill near Wadi Hodein	„	23	12	24	35	16	51	383
	396	Granite peak near Wadi Rahaba	„	23	11	11	35	20	35	355
	392	Rock in sea	(level datum).	23	10	55	35	35	57	0
	310	Isolated hill west of G. Etresia	summit.	23	10	35	34	25	23	703
	388	Hill near Wadi Hodein	„	23	10	33	35	16	32	309
	423	G. Kala	„	23	10	3	34	45	49	808
	503	G. Etresia	E. summit.	23	9	24	34	30	43	1,037
	303	Hill E. of G. Etresia	summit.	23	9	15	34	32	23	922
*	375a	G. Anfeib	beacon.	23	8	24	34	59	19	705
	364	Hill NE. of G. el Anbat	summit.	23	8	0	35	21	46	359
*	386	Close to Bir Shalatein	beacon.	23	7	57	35	36	23	13
	502	G. Etresia	summit.	23	7	53	34	31	24	1,038
	407	G. Kala	„	23	7	42	34	42	58	846
	311	Isolated hill north of G. Shigigat	„	23	7	16	34	24	39	901
	425	G. Kala	„	23	7	11	34	42	37	783
	424	G. Kala	„	23	6	51	34	42	30	739
	501	G. Etus	„	23	6	19	34	29	53	997
*	367a	G. el Anbat	beacon.	23	6	5	35	19	27	390
	312	G. Shigigat	conspicuous peak.	23	5	37	34	23	39	1,023
	406	G. Kala	summit.	23	5	16	34	42	19	629
	500	G. Aqab el Negum	„	23	3	26	34	27	20	1,149
	496	G. Natetiai	peak.	23	3	8	34	21	0	1,022
	499	Peak near Aqab el Negum	summit.	23	2	43	34	26	3	998
	498	Peak near Aqab el Negum	„	23	2	22	34	25	36	979
	497	Peak near Aqab el Negum	„	23	1	56	34	25	42	974
	495	G. Natetiai	peak.	23	0	49	34	22	7	1,164
	373	G. Niqrub el Tahtani	high pinnacle.	23	0	42	35	0	58	828
	373a	G. Niqrub el Tahtani	beacon.	23	0	39	35	0	53	829
*	369a	G. Beida	„	23	0	14	35	16	54	716
	494	G. Natetiai	peak.	22	59	35	34	22	22	977
	508	Peak in S. part of G. Feg	summit.	22	58	45	34	20	29	885
	391	G. Humariai	„	22	58	38	35	9	36	563
	382	Hill S. of Wadi Beida	„	22	58	10	35	12	58	631
	507	Peak in S. part of G. Feg	„	22	58	2	34	19	15	836
	381a	Hill S. of Wadi Beida	„	22	57	30	35	16	53	631
	379	G. Mismih	„	22	56	56	34	45	32	599
	381	Hill S. of Wadi Beida	„	22	56	47	35	17	3	615
	510	Conical hill	„	22	54	48	34	40	27	504
*	401	G. Kolaiqo	beacon.	22	54	13	35	24	35	320
*	374	G. Niqrub el Foqani	„	22	51	29	34	56	49	1,078
	509	G. Waqif	summit.	22	51	21	34	38	57	556
	466	Tree at Mersa Shab	centre.	22	50	56	35	47	3	1
	419	G. Um el Kalala	N. peak.	22	50	23	34	44	14	672
	506	G. Sheyenit	„	22	50	13	34	18	23	853
	505	G. Sheyenit	S. peak.	22	49	58	34	18	15	887
	415	G. Um el Kalala	„	22	49	26	34	44	18	655
	418	Hill close to Bir Madi	beacon.	22	47	46	35	1	39	556
*	408	G. Meneiga	„	22	47	35	35	11	7	1,032
*	402	G. Meneiga	highest point.	22	47	31	35	10	57	1,092
	430	Hill near Wadi Tikosha	summit.	22	46	29	35	20	11	443
*	410	Gemeida hill	beacon.	22	46	29	35	37	49	123
	437	Hill SSE. of Bir Meneiga	summit.	22	45	58	35	13	3	987
	434	Peak near Wadi Ti Ilak	„	22	44	36	35	17	54	774
	376	G. Shabih	highest peak.	22	44	26	34	50	21	1,117
	527	G. Mishbih	NW. summit.	22	44	21	34	41	23	1,321
	378	G. Mishbih	beacon.	22	44	18	34	41	20	1,316
	440	Ridge near head of W. Shellal elGharbi	high point.	22	44	15	35	12	18	1,092
	447	Qrein Salama	summit.	22	44	5	35	24	32	354
	435	Peak near Wadi Ti Ilak	„	22	44	4	35	17	46	849
	431	Hill N. of Wadi Muqur	„	22	43	55	35	18	52	670
	414	G. el Naga	smaller hill.	22	43	32	34	27	22	747
	91	G. Seiga	cairn.	22	43	31	34	16	16	905
	377	G. Mishbih	E. peak.	22	43	28	34	42	39	1,311
	526	G. Mishbih	peak.	22	42	52	34	41	27	1,353
	413	G. el Naga	N. peak.	22	42	42	34	27	46	787
	445	G. Tueiwi	summit.	22	42	40	35	5	56	836
*	403	G. Gerf	high point on ridge	22	42	15	35	11	43	1,339
	427	G. Gerf	minor summit.	22	42	13	35	13	32	1,327
*	370	G. Gerf	beacon.	22	42	6	35	12	16	1,419
	412	G. el Naga	S. peak.	22	42	0	34	28	25	827
	436	Peak near Wadi Muqur	summit.	22	41	58	35	18	22	778
	493	G. Mishbih	S. peak.	22	41	44	34	42	41	988
	432	Peak near Wadi Muqur	summit.	22	41	40	35	17	35	962
	383	G. Muqur	„	22	41	31	35	16	50	1,058
	433	Hill near Bir Sararat Seyet	„	22	41	16	35	0	57	797
	426	Peak near Wadi Diqdib	summit.	22	41	6	35	14	30	1,258
	438	Peak near Wadi Qadiloi	„	22	41	3	35	17	54	911
	429	Peak near Wadi Eirahimib	„	22	40	51	35	9	55	1,227
	371	G. Shweib	„	22	40	43	34	43	57	914
	428	Peak near Wadi Eirahimib	„	22	40	38	35	10	29	1,327
	531	Mt. near Bir Baaneit	„	22	40	1	35	18	15	909
	404	G. Gerf	minor summit.	22	39	59	35	10	7	1,318
	405	G. Korabkansi	„	22	39	39	35	0	44	1,052
	446	G. Korabkansi	N. peak.	22	39	35	34	59	32	1,176
	614	G. Hamra Dom	„	22	39	34	35	38	19	326
	439	Peak near Wadi Diqdib	summit.	22	39	17	35	16	11	1,028
*	372	G. Korabkansi	beacon.	22	39	16	34	59	55	1,230
	420	Peak near Wadi Difoteb	cairn.	22	39	11	35	10	21	1,298
*	417	G. Hamra Dom	beacon.	22	39	6	35	38	42	388
	450	Tibansi Tikam Ankwei	summit.	22	39	5	35	32	11	345
	475	Peak near Wadi Sherefa	„	22	38	20	35	11	42	1,344
	411	G. Hamra Dom	central peak	22	38	2	35	39	12	381
	473	Hill near Wadi Um Saha	summit.	22	37	54	35	17	56	926
	532	Hill near Wadi Um Saha	„	22	37	53	35	17	56	932
	444	G. Dreb	peak.	22	36	54	35	6	20	1,139
	615	G. Hamra Dom	S. peak.	22	36	48	35	39	36	317
	443	G. Dreb	peak.	22	36	41	35	7	0	1,148
	442	G. Dreb	„	22	36	40	35	7	46	1,137
	476	G. Dreb	„	22	36	16	35	9	15	1,176
	478	G. Dreb	„	22	36	10	35	8	21	1,224
	477	G. Dreb	„	22	36	1	35	8	56	1,191
	504	G. Kulyeit	summit.	22	35	50	34	16	38	724
	441a	G. Dreb	peak.	22	35	18	35	8	24	1,293
	533	Kilia Arib	summit.	22	35	2	35	18	46	647
	441	G. Dreb	peak.	22	35	0	35	8	36	1,288
	535	G. Dreb	„	22	34	15	35	9	42	1,095
	534	Tibashoi Tomakolat	summit.	22	33	4	35	19	40	464
*	449a	Kolmanab hill	beacon.	22	32	26	35	53	36	137
	566	Hill near Wadi Ibib	summit.	22	32	2	35	37	36	459
	619	Point near Kolmanab	—	22	31	55	35	52	40	110
	612	G. Medarai	minor peak.	22	31	23	35	13	5	1,103
	520	G. Medarai	summit.	22	30	58	35	12	5	1,299
	610	G. Medarai	minor peak.	22	30	56	35	14	37	922
	485	G. Anweiyib	N. summit.	22	30	22	34	53	42	871
*	567a	G. Eqrun (W. summit)	beacon.	22	30	10	35	37	9	473
	567	G. Eqrun	SE. summit.	22	30	0	35	37	18	468
	665	Adar Aweib Um Bishtit	summit.	22	29	28	35	33	2	455
	577	Granite hill	„	22	29	19	35	54	6	143
	522	G. Medarai	S. peak.	22	29	8	35	12	4	1,114
	528	G. Anweiyib	summit.	22	29	5	34	53	32	864
	587	G. Um Rasein	N. peak.	22	28	52	35	20	44	791
*	416	G. Um Rasein	beacon.	22	28	12	35	20	19	909
*	575	Einiwai hill	„	22	27	50	35	57	59	138
	521	G. Abu Hireiq	N. summit.	22	27	39	35	14	58	1,116
	609	Hill near Wadi Merdiyeb	summit.	22	27	21	35	15	51	856
	613	Tahaqayet	„	22	26	47	35	40	23	432
	596	Hill near Wadi Odruk	„	22	26	47	35	18	42	639
	595	Hill near Wadi Odruk	„	22	26	25	35	19	17	615
	582	Granite hill	„	22	26	23	35	56	20	155
	592	Near Wadi Odruk	peak.	22	26	9	35	20	9	627
	523	G. Abu Hireiq	highest point.	22	25	57	35	14	39	1,319
	581	Osnei hill	summit.	22	25	38	35	50	42	251
	455	Hill near Bir Um Bishtit	„	22	25	14	35	33	19	634
	472	Mt. near Wadi Abu Hireiq	„	22	24	43	35	16	13	1,256
	611	G. Adatalob Hadal	beacon.	22	24	38	35	48	22	381
	451	Titailibab	summit.	22	24	32	35	38	52	593
	459	G. Orgem	NW. peak	22	24	31	35	31	1	779
	576	G. Orgem	SE. peak.	22	24	21	35	31	11	775
	488	G. Anweiyib	NW. summit.	22	24	16	34	49	46	884
	471	Mt. near Wadi Abu Hireiq	summit.	22	23	56	35	16	41	1,226
	486	G. Anweiyib	SE. summit.	22	23	37	34	51	25	921
	664	Hill S. of Titailibab	summit.	22	23	26	35	39	5	554
	422	G. Abu Hodeid	beacon.	22	23	18	35	14	9	1,482
	572	G. Adatalob Adara	summit.	22	23	1	35	49	58	385
	603	Near Wadi Tikraneib	peak.	22	22	57	35	18	38	732
	454	G. Meis-heit-ar	summit.	22	22	37	35	34	44	717
	470	Mt. near Bir Abu Hodeid	„	22	22	31	35	17	33	1,074
	479	G. Mansur Diab	„	22	22	28	35	10	49	1,091
	469	Mt. near Bir Abu Hodeid	„	22	22	10	35	17	51	1,078
	457	Hill near head of Wadi Qidmib	„	22	22	3	35	32	42	738
	583	G. Tishushi Tiboki	minor summit.	22	22	0	35	57	12	284
	647	Abu Hodeid Oqla	summit.	22	21	29	35	17	51	992
	492	G. Um el Tiur el Tahtani	„	22	21	26	34	34	46	783
	666	G. Meis-heit-ar	„	22	21	15	35	34	48	721
	580	G. Tishushi Tiboki	highest point.	22	21	14	35	55	46	359
*	569a	Ti Keferiai	beacon.	22	21	0	35	49	47	494
	598	G. Hamra Tit	SW. peak.	22	20	6	35	20	44	642
	461	G. Qidmib	summit.	22	19	55	35	30	45	1,037
*	456	O Shakafa	„	22	19	44	35	34	42	751
	597	G. Geror	NE. summit.	22	19	31	35	52	4	434
	462	G. Qidmib	summit.	22	19	13	35	30	23	1,108
	464	G. Qidmib	„	22	19	4	35	29	18	1,070
	463	G. Qidmib	„	22	18	49	35	30	15	1,099
	616	G. Geror	high point.	22	18	37	35	50	18	510
	584	G. Qidmib	summit.	22	18	18	35	29	20	1,089
	453	Adar Aqdeib	summit.	22	18	6	35	37	51	736
	490	G. Um el Tiur el Foqani	„	22	17	56	34	41	14	946
	602	G. Geror	summit.	22	17	51	35	50	55	516
	649	G. el Sela	peak.	22	17	37	36	14	17	433
	487	G. Hadal Derqa	summit.	22	16	40	35	9	55	1,108
*	460	Hadal Aweib Meisah	beacon.	22	16	39	35	31	55	1,224
	650	G. el Sela	peak.	22	16	32	36	12	59	560
	491	G. el Adraq	summit.	22	16	22	34	35	3	770
	421	Qara Saba	„	22	16	7	35	41	34	778
	601	G. Um Seleim	„	22	15	58	35	21	35	1,098
	480	G. Hadal Derqa	SE. peak.	22	15	50	35	10	59	1,090
	585	Hadal Aweib Meisah	minor summit.	22	15	48	35	30	10	1,092
	604	G. Leqaq	summit.	22	15	40	35	20	8	1,192
	512	G. Heianai	NW. summit.	22	14	40	35	1	30	1,007
	668	G. Hamida	minor summit.	22	14	34	35	46	13	583
	620	Qash Amir	beacon.	22	14	31	36	12	20	724
	651	G. Sul Hamid	highest peak.	22	14	16	36	4	53	572
	568	G. Balatitda	summit.	22	13	56	35	58	5	592
	513	G. Hilwit Hasium	NE. peak.	22	13	50	35	14	38	1,037
	468	G. Adar Qaqa	summit.	22	13	47	35	19	0	1,606
	482	G. Heianai	SE. summit.	22	13	41	35	3	11	1,256
	618	G. Hamida	minor summit.	22	13	36	35	46	47	701
	608	G. Adar Qaqa	„	22	13	33	35	19	21	1,542
	448	G. Hamida	summit.	22	13	32	35	46	33	754
*	458	Halaib Fort	centre of top.	22	13	25	36	38	56	8
	556	G. Elba	peak near Bir Kansisrob.	22	13	21	36	22	23	820
	652	Hill E. of G. Balatitda	peak.	22	13	20	35	59	43	491
	555	Karam Elba	summit.	22	13	13	36	25	40	586
	525	G. Shanaiyet	„	22	13	4	34	49	43	907
	653	Hill near Wadi Warabeit	„	22	13	4	35	50	12	511
	676	G. Elba	peak near Wadi Yahameib.	22	13	2	36	20	54	935
	662	G. Balatitda	minor summit.	22	12	56	35	57	44	493
	489	G. el Hateib	summit.	22	12	44	34	43	18	854
	674	Hill near Wadi Siamtit	summit.	22	12	42	36	13	10	507
	516	G. Hilwit Hasium	SW. peak.	22	12	30	35	13	14	952
	669	Mt. south of Hadal Aweib Meisah	summit.	22	12	21	35	30	40	1,072
	481	G. el Arib	„	22	12	15	35	8	32	1,112
	579a	G. Um Ein	beacon.	22	11	52	35	39	4	901
	667	Hill near head of Wadi Warabeit	summit.	22	11	40	35	47	6	651
	467	G. Soaorib	„	22	11	33	35	20	13	1,469
*	536	G. Elba	beacon.	22	11	27	36	20	52	1,428
	621	G. Elba	minor peak.	22	11	16	36	23	44	1,102
	675	G. Elba	„	22	11	10	36	20	35	1,394
	483	G. Heleikonti	summit.	22	11	7	34	57	59	1,151
	573	G. Warabeit	„	22	11	1	35	47	52	794
	518	G. Soaorib	„	22	10	54	35	17	48	1,397
*	571	Adar Aweib	beacon.	22	10	50	35	54	0	620
	538	G. Elba	minor peak.	22	10	17	36	19	34	1,217
	606	G. Soaorib	summit.	22	10	14	35	21	25	1,349
	98	G. Muqsim	cairn.	22	10	11	34	1	12	825
	589	Mt. near Wadi Baueiwai	summit.	22	10	10	35	30	45	1,266
	537	G. Elba	highest point.	22	10	3	36	21	52	1,435
	617	G. Mashushenai	summit.	22	9	54	35	49	45	634
	605	G. Soaorib	peak.	22	9	50	35	21	45	1,383
	678	G. O Sir Eirab	summit.	22	9	24	36	20	56	842
	677	Hill near W. O Sir Hadal	„	22	9	7	36	15	56	724
	519	Peak near Wadi Kirir	„	22	8	24	35	18	27	1,328
	465	G. Soaorib	„	22	8	22	35	23	36	1,431
	590	Mt. N. of Wadi Adar Ameit el Sharqi	NE. peak.	22	8	16	35	31	2	1,294
	670	Hill near Wadi Aqwem	summit.	22	8	12	35	43	30	724
	578	Hill near Da-aiyob Wushaq	„	22	7	45	35	44	8	833
	681	G. Hanquf	minor peak.	22	7	45	36	16	54	789
	591	Mt. N. of Wadi Adar Ameit el Sharqi	SW. peak.	22	7	12	35	29	54	1,299
	682	G. Hanquf	minor peak.	22	6	54	36	17	18	877
	524	G. Um Reddam	summit.	22	6	23	34	59	55	1,109
	657	G. Miatit	W. peak.	22	6	14	35	34	12	1,229
	511	Mt. near G. Egat	summit	22	5	53	34	53	1	985
	484	G. Egat	„	22	5	39	34	52	15	1,145
	586	G. Miatit	SE. peak.	22	5	36	35	35	34	1,257
	659	Mt. near Wadi Adar Ameit el Gharbi	peak.	22	5	20	35	25	30	1,440
	540	G. Hanquf	N. peak.	22	4	52	36	18	45	1,397
	452	Hill near W. Di-ib	summit.	22	4	14	36	1	32	491
	655	G. Suruk	E. peak.	22	4	10	35	38	7	1,059
	588	G. Suruk	highest point.	22	3	50	35	35	28	1,327
	673	Hill near G. Suruk	peak.	22	3	46	35	40	16	846
	656	G. Shendib	„	22	3	40	35	36	1	1,275
	515	Mt. near G. Himeitra	„	22	3	17	35	17	52	1,134
	685	G. Shendib	„	22	3	8	36	13	44	1,427
	539	G. Shendodai	highest peak.	22	3	1	36	25	31	1,529
	672	Hill near G. Suruk	peak.	22	3	0	35	40	25	847
	661	G. Shiab	„	22	2	57	35	45	18	855
*	607	G. Hadarba	beacon.	22	2	53	36	47	23	217
	654	G. Shiab	highest point.	22	2	51	35	44	7	987
	517	G. Himeitra	summit.	22	2	46	35	14	19	1,231
	474	G. Is	cairn on summit.	22	2	36	35	28	4	1,736
	599	G. Is	peak.	22	2	24	35	27	35	1,659
	627	G. Shendodai	S. peak.	22	2	12	36	25	22	1,395
	684	Hill near G. Shendib	summit.	22	2	12	36	9	6	601
	600	G. Is	peak.	22	2	11	35	26	56	1,594
	671	Hill near G. Suruk	„	22	1	54	35	40	20	903
	593	Mt. east of G. Is	N. peak.	22	1	38	35	31	56	1,290
	570	G. Hanquf	highest point.	22	1	32	36	20	14	1,465
	640	G. Shendib	peak.	22	1	26	36	14	47	1,724
	641	G. Shendib	„	22	1	8	36	14	59	1,698
	594	Mt. east of G. Is	S. peak.	22	1	2	35	31	11	1,474
	642	G. Shendib	peak.	22	0	51	36	15	0	1,696
	543	G. Shendib	beacon.	22	0	48	36	16	30	1,912
	546	G. Shendib	peak.	22	0	46	36	14	49	1,674
	544	G. Shendib	peak.	22	0	45	36	16	10	1,852
	687	Hill near G. Shellal	summit.	22	0	40	36	9	2	614
	557	G. Shellal	peak.	22	0	39	36	30	30	1,269
	529	G. Shellal	E. peak.	22	0	34	36	30	45	1,279
	574	G. Shellal	highest point.	22	0	15	36	29	40	1,409
	545	G. Shendib	peak.	21	59	56	36	17	6	1,863
	547	G. Shendib	„	21	59	49	36	15	42	1,668
	550	G. Shendib	„	21	59	8	36	14	16	1,565
	645	G. Shendib	„	21	59	7	36	13	22	1,227
	549	G. Shendib	„	21	59	6	36	14	40	1,525
	644	G. Shendib	„	21	59	0	36	15	20	1,552
	646	G. Shendib	„	21	58	58	36	13	11	1,196
	660	Low hill near W. Shendib	summit.	21	58	24	36	4	25	500
	541	G. Qeda	E. peak.	21	56	24	36	28	11	1,850
	542	G. Qeda	W. peak.	21	56	16	36	26	12	1,872
	514	Hadal Aweib	summit.	21	52	40	35	22	26	1,780
	628	G. Asotriba	highest point.	21	51	55	36	30	26	2,216
	551	Eir Aweit	peak.	21	50	30	36	22	48	1,715
	552	Eir Aweit	„	21	49	56	36	23	1	1,678
	564	G. Obkeik	N. peak.	21	49	55	35	39	40	1,837
	548	G. Asotriba	S. peak.	21	49	30	36	30	40	2,082
	565	G. Obkeik	S. peak.	21	49	6	35	39	29	1,856
	553	Eir Aweit	highest peak.	21	47	57	36	22	40	1,853
	554	Eir Aweit	peak.	21	47	38	36	22	32	1,759
	658	Adar It	sharp peak.	21	47	1	36	19	14	1,170
	409		beacon.	21	44	21	34	36	53	—
	558	Arit	peak.	21	40	26	36	22	50	1,529
	559	Arit	„	21	39	25	36	22	32	1,772
	663	Karai Awa	summit.	21	39	18	36	10	21	1,056
	562	Arit	peak.	21	38	3	36	18	57	1,410
	560	Arit	highest peak.	21	36	51	36	23	27	1,810
	563	Arit	high peak.	21	36	1	36	19	52	1,727
	561	Arit	W. end of ridge.	21	35	50	36	22	48	1,532

Comparison of Positions determined on the Red Sea with those previously found in Official Marine Surveys.