pop-guns

"'...let us shoot popguns at least, against the solid bulwarks where folly and selfishness sit enthroned.'"  --Scenes Beyond the Western Border, Southern Literary Messenger 18 (August 1852) page 507; and Scenes and Adventures in the Army, page 355.

For three or four hours I was engaged in manufacturing pop-guns,but at last made over my good-will and interest in the concern to a lad of remarkably quick parts, whom I soon initiated into the art and mystery.
Pop, Pop, Pop, Pop, now resounded all over the valley. Duels, skirmishes, pitched battles, and general engagements were to be seen on every side. Here, as you walked along a path which led through a thicket, you fell into a cunningly laid ambush, and became a target for a body of musketeers whose tattooed limbs you could just see peeping into view through the foliage. There you were assailed by the intrepid garrison of a house, who levelled their bamboo rifles at you from between the upright canes which composed its sides. Farther on you were fired upon by a detachment of sharpshooters, mounted upon the top of a pi-pi.

Pop, Pop, Pop, Pop! green guavas, seeds, and berries were flying about in every direction, and during this dangerous state of affairs I was half afraid that, like the man and his brazen bull, I should fall a victim to my own ingenuity. Like everything else, however, the excitement gradually wore away, though ever after occasionally pop-guns might be heard at all hours of the day.--Typee chapter 19.

chit-chat

"Amid my flights—they shall be our chit-chat, not "light reading"—I shall often be sober, serious, if not sublime."
("Scenes Beyond the Western Border," Southern Literary Messenger 15 (June 1851): 372-373)

Curiously, "chit-chat" with the aside in which it occurs was deleted in revision for the 1857 book, thus:

"But amid my flights, I shall often be sober, serious, if not sublime. "
(Scenes and Adventures in the Army)

 "... a choice present of some very recherche chit-chat"
Pierre (1852)

great battles

"The French are the lads for painting action. Go and gaze upon all the paintings of Europe, and where will you find such a gallery of living and breathing commotion on canvas, as in that triumphal hall at Versailles; where the beholder fights his way, pell-mell, through the consecutive great battles of France; where every sword seems a flash of the Northern Lights, and the successive armed kings and Emperors dash by, like a charge of crowned centaurs?" Moby-Dick (1851)

"Amid my flights—they shall be our chit-chat, not "light reading"—I shall often be sober, serious, if not sublime. We will talk on all subjects, from the shape of a horse-shoe to that of the slipper of the last favorite—say the "divine Fanny," from great battles, or Napier's splendid pictures of such, down to the obscurest point of the squad drill—from buffalo bulls to elfin sprites." 
("Scenes Beyond the Western Border," Southern Literary Messenger 15 (June 1851): 372-373)

Napier must be military historian William Francis Patrick Napier,
and "splended pictures" the narrative descriptions of battles in Napier's
History of the War in the Peninsula 

UPDATE:
 "the divine Fanny" refers to Austrian ballet superstar Fanny Elssler (1810-1884).

The "Virtuoso's Collection" in Hawthorne's short story of that title (from Mosses from an Old Manse) holds

"Fanny Elssler's shoe, which bore testimony to the muscular character of her illustrious foot."

unbounded

"... only in unbounded confidence and interchangings of all subtlest secrets, can Love possibly endure."  Pierre (1852)

C.— "Is anything so beautiful as unbounded faith?" 

F.— "Listen! that's 'to horse.'"

C.— "Answer me then!"

F.— "Pshaw!—Of course it's beautiful; or rather sublime."

C.— "It is the very attribute of human love!"

["Scenes Beyond the Western Border," Southern Literary Messenger 19 (March 1853): 158 with the following comment by the narrator, which for some reason has been deleted in the 1857 book version,  

Scenes and Adventures in the Army]

July 8th.—Those who lack faith that the above was dreamed, spoken and scribbled, as described, lack, too, experience of the human mind, and prairie or desert influences and feelings.

bantering

 Pierre (1852):

"... of old, poetry was a consecration and an obloquy to all hapless modes of human life; but in a bantering, barren, and prosaic, heartless age, Aurora's music-moan is lost among our drifting sands, which whelm alike the monument and the dirge." 

"Scenes Beyond the Western Border," Southern Literary Messenger (August 1853), 461:

C.  "Ah! no bantering now—there is a dreamy art of more pretension still;—that would paint the heart;—that would fix the wandering thought;—that would delve for discoveries in the deep mine of man's nature!

"But I have been writing, Frank, something for your especial approval; I have been setting forth grim realities,—and most philosophically. I did strike at last, but most naturally and truly, a little vein of—"

F.  "—Poetry, perhaps?  by the merest accident in the world." 

eve of a snow-storm

August 1, 1851

"Proceeding homeward, we were overtaken by a cavalier on horseback, who saluted me in Spanish, to which I replied by touching my hat. But, the cavalier renewing his salutation, I regarded him more attentively, and saw that it was Herman Melville!" --Nathaniel Hawthorne

November 1851

"We left Lenox Friday morning, November 21, 1851, in a storm of snow and sleet, and took the cars at Pittsfield, and arrived at West Newton that evening."  --Nathaniel Hawthorne

 April 1852

"Amigo mio! Didn't you desert me on the eve of a snow-storm, like many another friend of so honest mouthing!"

good mornings with horses

December 1850

Do you want to know how I pass my time? — I rise at eight— thereabouts — & go to my barn — say good-morning to the horse, & give him his breakfast.  (It goes to my heart to give him a cold one, but it can’t be helped) Then, pay a visit to my cow....

-- Herman Melville, writing to Evert Duyckinck on 13 December 1850; letter transcribed in the 1993 Northwestern-Newberry Edition of Melville's Correspondence, edited by Lynn Horth, page 172.

Herman Melville, letter to Evert A. Duyckinck dated December 12, 1850
via The New York Public Library Digital Collections

 Pierre, 1852

Now, this grand old Pierre Glendinning was a great lover of horses. . .He said that no man loved his horses, unless his own hands grained them. Every Christmas he gave them brimming measures. "I keep Christmas with my horses," said grand old Pierre. This grand old Pierre always rose at sunrise; washed his face and chest in the open air; and then, returning to his closet, and being completely arrayed at last, stepped forth to make a ceremonious call at his stables, to bid his very honorable friends there a very good and joyful morning. 

Scenes Beyond the Western Border, August 1853

August 4th.[1845]—We marched at half-past 6 o'clock. That means that two hours earlier a trumpet had called us all from sleep to sudden labours; first, arms in hand,—there is an inspection,—then a "stable call," which the poor horses know well, although they have perhaps forgotten what a stable is, or have despaired ever to see one again; possibly they retain a vague memory of the grain, which, on a time, was served to them at that signal.  Now they whinny a morning greeting to their masters, and seem grateful for a little rubbing of their stiffened limbs, and removal to fresh grass.