30 
PHYSICAL ASPECTS OF ADEN . 
Bandar Towayih or Aden West Bay, more generally known as Aden 
Back Bay, is formed by the peninsula of Little Aden in the west and 
Aden on the east. It is about 8 miles broad from east to west, by 4 
miles deep. It is divided into two bays by a spit, which runs off half a 
mile to the southward of the small island of Aliyah. The entrance be- 
tween Ras Salil of Little Aden and Ras Tarshyne of Aden is 3J miles in 
width. The depths of water in the Western Bay are from 3 to 4 fathoms 
and the bottom consists of sand and mud. 
There are several islands in the inner bay. The eastern and princi- 
pal, named Jazirah Sawayih, usually called Slave Island, rises 300 feet 
high and is almost joined to the mainland at low-water springs. The 
others are called Marzuk Kabir, Kais-al-Hamman, Kalfatain or Twin 
Rocks, and Faringi. On the sand-spit, at the north side of the entrance 
into the inner bay, are two small islets named Jamah Aliyah. Opposite 
Ordnance Bay is the island Shaikh Ahmad or Flint Rock. 
4. Conditions of plant-life. — Water may be regarded as the most 
important of all factors which affect the plant. The water content of the 
soil acts upon the roots, regulating the water supply, and the humidity of 
the air exercises its influence upon the leaves, regulating the water loss. 
We understand by water content of a certain place the total amount 
of water in the layer of soil occupied by the roots. The water of the 
lower strata is not properly water content because it is of no use to the 
plant. No experiments have ever been made at Aden to show the exact 
amount of water content in the different localities of our area. As the 
water content, however, depends largely upon the effect of the other 
factors of the habitat which have an influence either direct or indirect 
upon the amount of water present, a short consideration of those factors 
concerned, viz*, soil, rainfall, humidity, and temperature, will help us to 
arrive at a satisfactory, though not exact, conclusion. 
(a) Soil . — The soil is of the greatest importance in determining not 
only the amount of water content, but also the kind of water, i.e, } the 
chemical substances found in solution. , The physical properties of the 
soil, viz.y its texture or fineness, determine the amount of water present, 
whilst the chemical nature of the soil indicates the kind and amount of 
nutrient material dissolved in the water. 
The structure of the soil ^has an almost absolute control upon the 
fate of the water that enters the ground, in addition to its influence upon 
the water that runs off. The amount of water drained away in response 
to gravity and the amount that can be raised from the lower strata by 
means of capillary action are entirely regulated by the physical properties 
of the ground. As the soils are formed from rock by the action of 
weathering, its structure will greatly depend on the particular process of 
