That rail-road-mangat
We say now railroad.
I wondered whether in the time railroads were a new concept railroad would not also be written as rail-road.
So I checked on Google Ngram the frequency of the words railroad and rail-road over time in books published.
What you can see is that the word rail-road really starts in 1820, peaks in 1835 and fades away in 1860.
The word railroad really starts also in 1820 and becomes from 1835 onward more frequent than rail-road, becoming our mainstream word.
Assuming that the use of rail-road was not "only" from the phrase of Poe himself, because that phrase is I guess not from 1820, and it was only in 1 book.
Nevertheless, it was easy to eliminate, because in the phrase the word Nassau is used.
So I made another check on the frequency of rail-road and Nassau. Here it shows that Nassau is highly less frequent than rail-road.
So from there it could very well be that Poe used rail-road as one word for our todays railroad.
That leaves mangat alone or in combination open.
So I asked Ngram to show the frequency of mangat alone, rail-road-mangat and the word nassau as reference.
It shows that the word mangat has a real low frequency and shows up after 1850 (whereby zero before 1850. You cannot see that from the graph, but if you are in Ngram, you can hoover with your cursor over a line to get the number)
Same conclusion
We say now railroad.
I wondered whether in the time railroads were a new concept railroad would not also be written as rail-road.
So I checked on Google Ngram the frequency of the words railroad and rail-road over time in books published.
What you can see is that the word rail-road really starts in 1820, peaks in 1835 and fades away in 1860.
The word railroad really starts also in 1820 and becomes from 1835 onward more frequent than rail-road, becoming our mainstream word.
Assuming that the use of rail-road was not "only" from the phrase of Poe himself, because that phrase is I guess not from 1820, and it was only in 1 book.
Nevertheless, it was easy to eliminate, because in the phrase the word Nassau is used.
So I made another check on the frequency of rail-road and Nassau. Here it shows that Nassau is highly less frequent than rail-road.
So from there it could very well be that Poe used rail-road as one word for our todays railroad.
That leaves mangat alone or in combination open.
So I asked Ngram to show the frequency of mangat alone, rail-road-mangat and the word nassau as reference.
It shows that the word mangat has a real low frequency and shows up after 1850 (whereby zero before 1850. You cannot see that from the graph, but if you are in Ngram, you can hoover with your cursor over a line to get the number)
If you replace that dash with, say, a semicolon you get
Parachutes and rail-roads; mantraps and spring-guns!
Same conclusion