Almost at the same time there came to me news from the Gulf of Mexico. Perhaps you will remember that I wrote a novel about some islands there. I used to pass my summers in those islands. They were about sixty miles from the city of New Orleans. Well, on October 4th, a storm burst over that coast, killing more than 2000 people. The island of Grand Isle was covered by the sea in the night; and everything--houses, trees, and people--carried away. Hundreds I used to know are dead. It is a year of storms and calamities, surely, in all parts of the world.
I will write a better letter later: I am writing now to answer your questions about those sentences:--
(i) "Choppy"--"chopped" or "chapped" by cold: "chapped hands"--hands of which the skin is _cracked_ by frost. "His hands are all chapped"--that is, all _roughened_ by frost. "Choppy" is not so often used as "chapped:" it is a poetical use of the word.
(ii) "He had torn the cataracts from the hills." You must remember here Winter is personified as a monstrous giant. "Cataracts" is used in the sense of "waterfalls." The waterfalls are frozen into solid masses of ice. Winter, the giant, breaks them off, and hangs them round his waist.
(iii) "And they clanked at his girdle like _manacles_" (from Latin _manus_, "hand") (you spelled the word wrong: it is "manacles"). "Manacles," iron fetters for the hands;--handcuffs. They are made in pairs, fastened together by a chain, and closed by a key. They _clank_ when they strike together,--(i. e.) make a ringing metallic noise--because they are of fine steel usually. The sound made by iron is "clank"--"_to_ clank" (verb), "_a_ clank" (noun). Why does Shelley use such a simile? Because Winter is like a jailer, like the keeper of a prison. He fastens up, or imprisons, the rivers, lakes, and ponds with ice. So he is described as a keeper of prisoners,--with manacles or handcuffs hanging to his waist, ready for use. Ice striking against ice makes a ringing noise, very much like iron--sometimes. The comparison is very strong.
And why does he put his chapped finger to his lip? To put the first finger on the lips is a sign for "Be silent!" "Do not speak!" In winter the world becomes silent. The birds are gone; the insects are dead.
