in March, May, July, October, and December. Critical temperatures Favorable travel temperature range: below Optimum travel temperature: Glow temperature: Fire point: Autoignition temperature: - Autoignition temperature (for oily cotton): A temperature range of is the optimal range for mold development. At temperatures below , rotting of wet cotton stops. Damaged cotton is sometimes stored at these temperatures to prevent further deterioration. Egypt has a unique climatic temperature that the soil and the temperature provide an exceptional environment for cotton to grow rapidly. British standard yarn measures 1 thread = 1 skein or rap = 80 threads () 1 hank = 7 skeins () 1 spindle = 18 hanks () Fiber properties Depending upon the origin, the chemical composition of cotton is as follows: Cellulose 91.00% Water 7.85% Protoplasm, pectins 0.55% Waxes, fatty substances 0.40% Mineral salts 0.20% Morphology Cotton has a more complex structure among the other crops. A matured cotton fiber is a single, elongated complete dried multilayer cell that develops in the surface layer of cottonseed. It has the following parts. The cuticle is the outer most layer. It is a waxy layer that contains pectins and proteinaceos materials. The primary wall is the original thin cell wall. Primary wall is mainly cellulose, it is made up of a network of fine fibrils (small strands of cellulose). The winding layer is the first layer of secondary thickening it is also called the S1 layer . It is different in structure from both the primary wall and the remainder of the secondary wall. It consists of fibrils aligned at 40 to 70-degree angles to the fiber axis in an open netting type of pattern. The secondary wall consists of concentric layers of cellulose it is also called the S2 layer, that constitute the main portion of the cotton fiber. After the fiber has attained its maximum diameter, new layers of cellulose are added to form the secondary wall. The fibrils are deposited at 70 to 80-degree angles to the fiber axis, reversing angle at points along the length of the fiber. The lumen is the hollow canal that runs the length of the fiber. It is filled with living protoplasm during the growth period. After the fiber matures and the boll opens, the protoplast dries up, and the lumen naturally collapses, leaving a central void, or pore space, in each fiber. It separates the secondary wall from the lumen