_Ride Through Palestine_, Dr. Dulles tells of a great oak near
Hebron known as 'Abraham's oak,' supposed to occupy the ground where the
patriarch pitched his tent under the oaks of Mamre. It is an aged tree,
and a grand one. Here is a picture of it, from the _Ride_[6]. The crests
and sides of the hills beyond the Jordan are still clothed, as in
ancient times, with magnificent oaks.

[6] See page 85

"We get a good idea of the strength and durability of this wood from the
fact that there is an old wooden church near Ongar, in Essex, the nave
of which is composed of half logs of oak roughly fastened by wooden
pegs. The ancient fabric dates back to the time of King Edmund, who was
slain by the robber Leolf in the year A.D. 946. The oaken church was
hurriedly put together--according to report--in order to make a
temporary receptacle for the body of the murdered prince on its way to
burial. Be that as it may, it was afterward used as a parish church,
and, though the oaken logs are corroded by the weather, they are still
sound, and, having been beaten by the storms of a thousand winters, bid
fair to defy those of a thousand more."

"I should think, then," said Malcolm, "that people would always build
their houses with oak if it lasts so long."

"Yet they do not do this even in England," was the reply, "where the
trees grow to such an immense size and the ancient buildings still in
existence prove the great endurance of the oak. Now brick and stone and
iron are used, which outlast any wood. And now," continued Miss Harson,
"I am going to tell you something about a foreign species of this tree
which I am sure will surprise you. It is found in the South of Europe
and in Algeria, and is called the _cork oak_."

"'The _cork_ oak'!" exclaimed Clara, quite as much surprised as she was
expected to be. "Do the corks that come in bottles grow on it?"

"Not just in that shape, dear, but they are made from its bark. The
outside bark, or _epidermis_, consists of a thin, transparent,
tissue-like substance, which covers not only the bark, but the whole of
the tree, stem, leaves and branches, and beneath the epidermis is found
a layer of cellular tissue, generally green. It covers the trunk and
branches, fills up the spaces between the veins of the leaves and
contains the sap, which flows in canals arranged for it in the most
beautiful and wonderful manner. In one species of oak this layer--which
is called the _suber_--assumes a peculi