Everything I'm finding says Mirror Lake, too. If you pull up those ebay postcards on the link provided by TomT and take a moment to read thru them all, it's all "Mirror Lake"...
This might be of interest...
Here's one excerpt (typos are not my own - this is a copy/paste)
from: "The Granite Monthly, New Hampshire Magazine", 1903:
John A. Edgerly.
Chairman Committeeman Agricultural College.
ence. Returning to Tuftonborough,
after teaching a few terms,
he engaged
in farming and later in the summer
boarding business, " Edgerly Farm "
having now become well known among
the many summer visitors who flock to
that part of the lake region. He is a
Republican in politics, by which party
he has been elected a member of the
board of selectmen and to minor town
offices and finallv to the legislature.
He has also been on the board of edu-
cation. Mr. Edgerly belongs to none
of the secret societies except the
Grange. In this he has taken all the
degrees up to and including the
seventh, that of the National Grange.
He has served as master of Tufton-
borough Grange, No. 142. He has also
been lecturer, overseer, and master of
( larroll County Pomona Grange, and
district and Pomona deputy for the
State Grange. Mr. Edgerly is a mem-
ber of and takes an active part in the
works of the Second Christian church
of Tuftonborough. He has been an
indefatigable worker in the interest of
his town and the surrounding region,
having been especially influential in
the establishment of a steamboat line
between The Weirs and Melvin Vil-
lage. He was married to May C.
Blake of Moultonborough, December
25, 1880. They have one child, Ed-
win B., now a student at Brewster
academy, Wolfeborough.
----
The boarding house is also listed in several books by Boston & Maine RR as a place of interest/place to stay.
----
Additionally... there's an Edgerly Cemetary
HERE and I would guess that the farm was very close by... a satellite map shows quite a bit of clearing to the right of that marker, if you zoom in a bit. I've not be able to determine if the building is still there or not, as the Registry of Deeds for Carroll County does not have an online database.