The procedure for assessing damage on state land has six steps.

First the zero point is set. Ahmad fixes it at the corner of the low wall, where the road comes out of the bend.

Then the length is measured. The iron rule is in segments. The third segment bent on him three years ago, and he always opens it only as far as the second, one metre eighty at a time.

Eighty-six metres.

Then the width is measured. Two forty, constant.

Then the stones are counted on three samples of one square metre, one at the start, one halfway, one at the end. Then the average is taken. Then it is multiplied.

The number that comes out is fifteen thousand and a little more.

Fifth step: the soil degradation coefficient is applied. For stone it is zero. Stone does not degrade, it moves.

Sixth step: the value is written in the box.

The sixth step has a footnote in the manual. The note says that the value is determined according to the method most appropriate to the case. It does not say which.

Ahmad knows that note by heart. He has known it for eleven years and it had never been of any use to him.

The court has already decided. The judgment is of the third of September.

Four convicted, all from the area of Bani al-Harazi. Fifty thousand rial each, old currency. Four hundred thousand rial in court costs to the Authority. The value of the stones jointly, to be quantified.

To be quantified means Ahmad.

The chief summoned him at seven. He spoke about the slope above the bend. He said it has been state land since the survey and that it is written down. Then he spoke about last year's quarry, the one that took a whole flank away towards the wadi, and about the time he had gone to look and had nothing in his hand to show, because no one had ever put a value on the stones of that slope.

Ahmad listened standing. He did not sit because the chief had not sat.

The chief said one thing only about the assessment. He said the file has to hold.

Then he opened the window, because at seven in the morning in the Authority's office it is already thirty degrees, and he closed the conversation.

Ahmad took the rule, the form, the manual and the water bottle. He walked twenty-two minutes to the bend.

Then he went to the site.

At the site there were people. They had gone back to work, the same four and others with them, and they were paving the uphill stretch, the one that floods. The stretch was growing while he measured.

No one said anything to him. One of them moved his water bottle into the shade.

They brought the stones up with a wheelbarrow. One wheelbarrow only, and the same man always pushed it, and the others loaded.

He held the rule open in mid-air for a moment, before folding it shut, and looked at the new stretch, where the stones were not yet in anyone's count.

Then he folded the rule shut, seven clicks, and said out loud the number of stones missing from the total.

The chief takes the form. He turns it round on the table. He rests his thumb on the empty box and keeps it there.

He talks about the weather. He talks about the road to Sanaa. Then he says the name of the quarry. He says it once only and adds nothing.

Ahmad takes the form. He carries it back to his table. He opens the manual at the page of the methods.

There are two methods. First: quarry value, worked stone, per unit. Second: value of the material as it lies, in bulk, per cubic metre. Both can be written. Both hold on appeal.

He takes the pen. He writes in the box the value of the material as it lies. He writes the figure in words and then in numbers, as the form requires.

Then he does something he was not asked to do. He starts a new line. In the notes line he writes the result of the other method, in full, with the calculation formula beside it.

He reads it over. He crosses nothing out.

He signs at the bottom right, where the assessor's signature goes, and puts the date.

The chief reads the notes line. It takes him very little.

He says nothing. He hands the form back. He points with the pen to the place for the countersignature.

Ahmad countersigns. He numbers the file. He passes it to the registry office. The registry clerk opens the register, copies out the number, puts on the round stamp, then the long one with the date, then puts the file back on the third shelf.

The third shelf is the one for closed cases. The second is the one for cases in progress. The first has been empty since they removed the land registry section.

At that point the chief says who the quarry case is to be assigned to. He says another name.

Ahmad goes back to his desk. He leans the rule against the table leg, on the inside, where it always stays.

In the evening he goes to the uphill stretch. The paving is finished. He walks the whole of it, from the bottom, counting his steps and holding the numbers in his head in groups of three. He reaches the top. He works out the length.

He is out by one metre sixty, short.