Turkey Military stamp

Nice stamps!  Makes you wonder why and how they were perforated in that octagonal shape.

I found this May 1898 London Philatelist article about the issue that explains a little bit about the perforations.

THESSALY.—The retiring Turk, eager to
preserve some tangible evidence of the occupation
of Thessaly, has caused a series of
five stamps to be issued, a set of which is to
hand from Messrs. Whitfield King & Co.
At the time of writing, transport vessels
are awaiting to embark the Turkish troops
at present in Thessaly. It seems scarcely
credible that these labels should have any
official connection with the Turkish Post
Office, but they have been issued by Imperial
Irade", and have included in the design the
Thougra, or arms of the Sultan. Le T.-P.
informs us that it is the desire of the Government
in issuing the stamps to leave on record
some souvenir of the occupation of Thessaly
by the Turkish Empire. At the Yildiz exhibition,
the stamps remaining over, after
the evacuation of Thessaly, will be sold at
an enhanced value, the proceeds being used
for the benefit of the families of those soldiers
who fell in the late war.
The stamps are octagonal in shape, and
are perforated so as to give a square perforation,
or an octagonal one, at will, this
latter feat being possible owing to the stamps
being printed with a margin of paper half an
inch in width between each, both horizontally
and vertically.
The design includes, in Turkish characters,
the following inscription: " Special for Thessaly,
that part of the country conquered."
The values are 10 and 20 paras, I, 2, and
5 piastres.
Although we have gone to some trouble to
describe these stamps, it is scarcely needful
to say we consider that they are probably
unnecessary and speculative.

The following paragraph, which appeared
in an evening London newspaper, bears out
the spirit of the foregoing remarks :—

" There has been a great run on the new
postage stamps for Thessaly, which the
Turkish Government caused to be circulated
last week. These stamps are of the values
of 5, 2, and i piastre, and of 20 and 10
paras ; and so eager were collectors to
possess the new stamps that on the third
day following their introduction those valued
5 and 2 piastres were all bought up, and
changed hands at eighteen shillings. The
stamps of smaller value brought four shillings.
The traders in these stamps were Turkish
officers and Civil servants, who, now that
the evacuation of Thessaly is taking definite
shape, evidently thought the first and only
issue of stamps by the Turkish Government
was an opportunity for making money not to
be thrown away." 

This is an example of a stamp where some of the forgeries have clearer impressions than the originals.