I passed another Wall turret, with only the back wall standing. Just after that came a wide nick, full of trees, alders and hawthorn, still dripping from the recent rain. The sweet smell of wet young bracken greeted me all the time. Before the next nick there are some good bits of Wall, seven or eight courses high. So up and down went the Wall, and I with it, clinging to the sides of the steepest nicks, with unswerving loyalty to plan! Sometimes its northern face, overhanging the cliffs, presented an unbroken surface of facing-stones for 5 or 6 feet; sometimes there was but a mere mound. Several of the nicks are little groves of trees. Sheep were grazing everywhere, and rabbits still abounded. You might see them sitting up on the Wall, the evening sun shining through their transparent ears, with a (literally) blood-red glow; or playing all sorts of pranks, apparently without fear of intrusion. The Wall finally runs straight to the edge of Greenhead Quarry, where an iron fence is placed, to keep the unwary (or too-faithful!) follower of the Wall from tumbling over the cliff, as, alas! the Wall has already done. In the 1884 edition of Dr. Bruce's Handbook, there is an interesting picture of a Wall turret standing {152} on the very edge of the quarry. Now it has gone; it has simply been quarried away! Not only was the rain over, but the sun was sending long level golden rays over the tops of the hills as I came to the quarry; and this was the end of my Wall-walk for the day. They were standing at the door looking out for me when I arrived at the house where I was to spend the night, for I had been delayed by the storm. I had felt indignant about that Wall turret, but the next day I realized the necessity of forgiving my enemies (in the shape of the Greenhead Quarry Company), for I accepted an invitation to visit the quarry before continuing my walk. [Illustration: THORNY DOORS GAP, WITH NINE NICKS OF THIRLWALL IN THE DISTANCE] It is a whinstone quarry, needless to say, for it is busy cutting a large slice out of the basaltic ridge on which the Wall has clung for so many miles. I had previously been puzzled by the appearance of the Cawfields Quarry, which is quite a landmark for miles, making a rich yellow patch in the landscape. If basalt is a dark blue-grey stone, how can it make a yellow patch? Now was my opportunity to inquire. The manager told me that although whinstone is a dark blue-grey stone, yet it has a yellow "skin" which forms on it under certain conditions, as, for example, when the earth has got in through cracks. It is not a good building-stone, apart from its colour and the difficulty of dressing it, for capillary attraction draws the water {153} up through it very freely, so that it always seems damp. "The Romans were not able to work it, as it can't be worked with wedges."