There are several books that contain a lot of interesting information about the kilns, along with copyrighted maps and photos. Two particularly outstanding books are written by Bill Gove, as follows:
1) "Logging Railroads of New Hampshire's North Country"
2) "J.E. Henry's Logging Railroads"
From descriptions contained in these books, it's my understanding that kilns were built against a hillside which facilitated the loading of short hardwood logs through an opening in the top portion of the kiln. To produce the charcoal, combustion within the kiln was controlled so that the wood was thoroughly charred, but not burned. Adjacent to the bottom portion of the kilns was a railroad which made it convenient to load the charcoal onto railcars and transport it to markets.
There is at least one photo of the kilns at Zealand (shown below) which is not copyrighted and is available on the Internet.
There were several charcoal kilns within a several mile radius of the current-day Mt. Washington Hotel. On 29-December, I set off to visit the general locations of two of the many spots where kilns were known to exist. One location was along the west bank of the Zealand River (a few tenths of a mile south of the Ammonoosuc River). And, the other location was near a former farm settlement known as Twin Rivers (a short distance off the current-day Mt. Clinton Road).
Although I'm a bit uncertain, it is my understanding that at both the Zealand and the Twin Rivers location, the only existing remnants of the kilns are some scatterings of bricks at or near the surface of the earth. Regardless, I did find some bricks strewn on the ground at the Twin Rivers location (shown below).
No bricks were found in the Zealand area. It could have been because I was at the wrong location, or simply that the light-covering of snow was just enough to obscure the bricks.
Even if I was at the wrong location, some of my findings make me think that perhaps I was at least close to it! At a couple of separate spots, I found sections of railway track, such as shown in the next two photos. (The first snapshot is easily recognizable as rail track. In the second photo, the segment of track is laying on its side and only the bottom of the rail is visible.)
Also spotted at the Zealand location is what might be strapping (hoops) for wooden barrels (photo below).
And finally, there was yet another metal object found at this location, but I have no idea what it might be (photo below)! I'm still kicking myself for not taking time to properly assess this object. I fully intended to go back to it and at least make some rough measurements. However, I got distracted by looking for bricks from the kilns, and then forgot to double-back to it. Just to give some rough idea of its size, my guess is that the diameter was probably at least 8 inches, and the visible height was at least 6 inches.
To sum it up, my discoveries were small compared to relics found by others. Nonetheless, it was still thrilling to find these few remnants of the past. I owe a debt of gratitude to my friend Joanne Jones for rekindling (no pun intended) my curiosity about the charcoal kilns of the late 19th century. And, I'm most appreciative to David Govatski for his advice regarding the general locations of the kiln sites.