The question of crossing the canal or dominating it in any sense was for the Turks largely a question of bringing to bear a superior force of artillery--a task that had only to be stated to reveal its difficulties. No force with smaller or fewer guns would hope to cross the Suez in the face of the concentration of artillery and naval gunfire that the British could bring to bear at any threatened point. The defenders on the western side of the canal had the additional advantage of railway communication running along the entire canal from Suez to Port Said, and connecting with interior bases. There were five points from which, once having conquered the desert and reached the canal, the invaders could advantageously launch an attack or attacks upon the canal defenses. The first is just south of El Kantara, where the old sea road crosses the Suez. Just south of Ismailia a group of heights on the east bank provides a second opportunity. The third is found at the point called the Plateau of Hyena. The fourth is just north of the Bitter Lake, and the fifth is to the south of the same body of water. Late in December, 1914, Djemel Pasha began active preparations for an advance upon the canal. This campaign the Turks later called a reconnaissance in force and as, of their total strength of 50,000 men, only 12,000 at the outside and possibly less were used, the limited term seems justified. Although the southern route was used by the main force, a small force eluded the watchfulness of the Anglo-French naval patrol operating along the shore commanding the first day's march of the northern, or sea road, and ultimately struck at El Kantara. Furthermore, sometime before one of these two forces--the larger, or southern--reached the vicinity of the canal, it split and conducted an independent attack at Suez.