Robert Fisk: 'Mubarak will go tomorrow,' they cried as rocks and firebombs flew

From the House on the Corner, you could watch the arrogance and folly yesterday of those Egyptians who would rid themselves of their "President". It was painful – it always is when the "good guys" play into the hands of their enemies – but the young pro-democracy demonstrators on the Tahrir Square barricades carefully organised their Cairo battle, brought up their lorryloads of rocks in advance, telephoned for reinforcements and then drove the young men of Hosni Mubarak back from the flyovers behind the Egyptian Museum. Maybe it was the anticipation that the old man will go at last today. Maybe it was revenge for the fire-bombing and sniper attacks of the previous night. But as far as the "heroes" of Egypt are concerned, it was not their finest hour.

The House on the Corner was a referee's touchline, a house of late 18th century stucco with outer decorations of stone grapes and wreaths and, in the dank and derelict interior, a broken marble staircase, reeking cloth wallpaper and wooden floors, groaning under bag after bag of stones, all neatly broken into rectangles to hurl at the accursed Mubarakites. It was somehow typical that no one knew the history of this elegant, sad old house on the corner of Mahmoud Basounee Street and Martyr Abdul Menem Riad Square. It even had a missing step on the gloomy second floor with a 30ft drop that immediately brought to mind the staircase in Stevenson's Kidnapped, and its vertiginous drop illuminated by lightning. But from its crumbling balconies, I could watch the battle of stones yesterday and the brave, pathetic attempts of the Egyptian army to contain this miniature civil war, preceding, as it does, another Sabbath day of prayers and anger and – so the protesters happily believe yet again – the very final hours of their accursed dictator.

The soldiers manoeuvred through the field of rocks on the highway below, trying to position two Abrams tanks between the armies of stone throwers, four soldiers waving their hands above their heads – the Egyptian street sign for "cease fire".

It was pathetic. The army needed 4,000 troops here to stop this battle. They had only two tank crews, one officer and four soldiers. And the forces of democracy – yes, we have to introduce a little cynicism here – cared nothing for the forbearance of the soldiers they have been trying to woo. They formed in phalanxes across the road outside the Egyptian Museum, each holding a shield of corrugated iron, many of them shouting "God is Great", a mockery of every Hollywood Roman legion, T-shirts instead of breastplates, clubs and the police night-sticks of Mubarak's hated cops instead of swords. Outside the House on the Corner – cheerfully telling me it belonged to anyone – stood a man holding (believe me, reader) a 7ft steel trident. "I am the devil," he cheerfully roared at me. This was almost as bad as the horse and camel attack by the Mubarakites on Wednesday.

Five soldiers from another unit seized a tray of Molotov cocktails from the house next door – Pepsi bottles are clearly the container of choice – but that constituted the entire military operation to disarm this little freedom militia. "Mubarak will go tomorrow," they screeched; and then, between the two tanks, at their enemies 40ft away, "Your old man is leaving tomorrow." They had been encouraged by all the usual stories; that Barack Obama had at last called time on Mubarak, that the Egyptian army – recipients of an annual $1.3bn aid – was tired of being humiliated by the President, infuriated by the catastrophe that Mubarak had unleashed on his country for a mere nine more months of power.

This may be true. Egyptian friends with relatives among the officer corps tell me that they are desperate for Mubarak to leave, if only to prevent him issuing more orders to the military to open fire on the demonstrators.

But yesterday, it was Mubarak's opponents who opened "fire", and they did so with a now-familiar shock of stones and iron hub-caps. They crashed on to the Mubarak men (and a few women) on the flyover, ricocheted off the top of the tanks. I watched their enemies walk – just a few of them – into the road, the rocks crashing around them, waving their arms above their heads in a sign of peace. It was no use.

By the time I climbed down that dangerous staircase, a lone Muslim imam in a white turban and long red robe and an absolutely incredible – distinguished may be the correct word – neatly combed white beard appeared amid the stones. He held a kind of whip and used it to beat back the demonstrators. He, too, stood his ground as the stones of both sides broke around him. He was from those who would rid themselves of their meddlesome President but he, too, wanted to end the attack. A young protester was hit on the head and collapsed to the ground.

So I scampered over to the two tanks, hiding behind one of them as it traversed its massive gun-barrel 350 degrees, an interesting – if pointless – attempt to show both sides that the army was neutral. The great engines blasted sand and muck into the eyes of the stone throwers, the whining of the electrical turbine controlling the turret adding a state-of-the-art addition to the medieval crack of rocks. And then an officer did jump from the turret of one behemoth and stood with the imam and the lead Mubarakites and also waved his arms above his head. The stones still clanged off the highway signs on the flyover (turn left for Giza) but several middle-aged men held out their arms and touched each other's hands and offered each other cigarettes.

Not for long, of course. Behind them, in the square called Tahrir, men slept beneath the disused concrete Metro vents or on the mouldy grass or in the stairwells of shuttered shops. Many wore bandages round their heads and arms. These wounds would be their badges of heroism in the years to come, proof they fought in the "resistance", that they struggled against dictatorship. Yet not one could I find who knew why this square was so precious to them.

The truth is as symbolic as it is important. It was Haussmann, brought to Egypt by Ismail under notional Ottoman rule, who built the square as an Etoile modelled on its French equivalent, laid over the swamps of the regularly flooded Nile plain. Each road radiated like a star (much to the chagrin, of course, of the present-day Egyptian army). And it was on the Nile side of "Ismailia" square – where the old Hilton is currently under repair – that the British later built their vast military Qasr el-Nil barracks. Across the road still stands the pseudo-Baroque pile in which King Farouk maintained his foreign ministry – an institution which faithfully followed British orders.

And the entire square in front of them, from the garden of the Egyptian Museum to the Nile-side residence of the British ambassador, was banned to all Egyptians. This great space – the area of Tahrir Square today – constituted the forbidden zone, the land of the occupier, the centre of Cairo upon which its people could never set foot. And thus after independence, it became "Freedom" – "Tahrir" – Square; and that is why Mubarak tried to preserve it and that is why those who want to overthrow him must stay there – even if they do not know the reason.

I walked back last night, the people around me hopeful they could endure the next night of fire-bombs, that today will bring the elusive victory. I met a guy called Rami (yes, his real name) who brightly announced that "I think we need a general to take over!" He may get his wish.

As for the House on the Corner, well, Mahmoud Basounee Street is named after an Egyptian poet. And the stone-battered sign for the Martyr Abdul Menem Riad attached to the House on the Corner honours a man whose ghost must surely be watching those two tanks under the flyover. Riad commanded the Jordanian army in the 1967 Six Day War and was killed in an Israeli mortar attack two years later. He was chief of staff of the Egyptian Army.