About the time that these occurrences took place, the Egyptian army advanced into those parts of the city from which Caesar had withdrawn, producing those terrible scenes of panic and confusion which always attend a sudden and violent change of military possession within the precincts of a city. Ganymede brought up his troops on every side to the walls of Caesar's citadels and intrenchments, and hemmed him closely in. He cut off all avenues of approach to Caesar's lines by land, and commenced vigorous preparations for an assault. He constructed engines for battering down the walls. He opened shops and established forges in every part of the city for the manufacture of darts, spears, pikes, and all kinds of military machinery. He built towers supported upon huge wheels, with the design of filling them with armed men when finally ready to make his assault upon Caesar's lines, and moving them up to the walls of the citadels and palaces, so as to give to his soldiers the advantage of a lofty elevation in making their attacks. He levied contributions on the rich citizens for the necessary funds, and provided himself with men by pressing all the artisans, laborers, and men capable of bearing arms into his service. He sent messengers back into the interior of the country, in every direction, summoning the people to arms, and calling for contributions of money and military stores. These messengers were instructed to urge upon the people that, unless Caesar and his army were at once expelled from Alexandria, there was imminent danger that the national independence of Egypt would be forever destroyed. The Romans, they were to say, had extended their conquests over almost all the rest of the world. They had sent one army into Egypt before, under the command of Mark Antony, under the pretense of restoring Ptolemy Auletes to the throne. Now another commander, with another force, had come, offering some other pretexts for interfering in their affairs. These Roman encroachments, the messengers were to say, would end in the complete subjugation of Egypt to a foreign power, unless the people of the country aroused themselves to meet the danger manfully, and to expel the intruders.