the lord of the rings - What modern day items are mentioned in JRRT's writings?

I read LOTR again recently and noticed that they mentioned top hats, matches and tomatoes, all items that don't really fit the era. (top hats maybe)

A friend recently mentioned to me that Tolkien regretted including tomatoes in LOTR as they are a relatively newer fruit and not something that fits the time period.

Is there any other time travelling items mentioned in any of JRRT's writings?

Bonus points for any of Tolkien's writings on this topic.

Answer

Pop-guns

"Carefully! Carefully!" he said. "It is not like you, Bilbo, to keep friends waiting on the mat, and then open the door like a pop-gun!"

_{- The Hobbit, Chapter 1: An Unexpected Party}

Umbrellas

Frodo [...] escorted her firmly off the premises, after he had relieved her of several small (but rather valuable) articles that had somehow fallen inside her umbrella.
_{- The Fellowship of the Ring, Chapter 1: A Long-expected Party}

And again, also Lobelia:

'"I'll give you Sharkey, you dirty thieving ruffians!" says she, and ups with her umbrella and goes for the leader, near twice her size. So they took her. Dragged her off to the Lockholes, at her age too. They’ve took others we miss more, but there’s no denying she showed more spirit than most.'"

_{- The Return of the King, Chapter 18: The Scouring of the Shire}

Buttoned waistcoats

If Balin noticed that Mr. Baggins' waistcoat was more extensive (and had real gold buttons), Bilbo also noticed that Balin's beard was several inches longer.
_{- The Hobbit, chapter 19: The Last Stage}

Clocks

"If you had dusted the mantelpiece, you would have found this just under the clock," said Gandalf, handing Bilbo a note (written, of course, on his own note-paper).

_{- The Hobbit, chapter 2: Roast Mutton}

Lamps

"Just then I saw the eyes: two pale sort of points, shiny-like, on a hump at the near end of the log... But whether those two lamps spotted me moving and staring, or whether I came to my senses, I don't know."
_{- The Fellowship of the Ring, chapter 21: The Great River}

Golf

He charged the ranks of the goblins of Mount Gram in the Battle of the Green Fields, and knocked their king Golfimbul's head clean off with a wooden club. It sailed a hundred yards through the air and went down a rabbit-hole, and in this way the battle was won and the game of Golf invented at the same moment.

_{- The Hobbit, chapter 1: An Unexpected Party}

Clarinets

Bombur produced a drum from the hall; Bifur and Bofur went out too, and came back with clarinets that they had left among the walking-sticks.
_{- The Hobbit, chapter 1: An Unexpected Party}

Matches

"Raise the Shire!" said Merry. "Now! Wake all our people! They hate all this, you can see: all of them except perhaps one or two rascals, and a few fools that want to be important, but don’t at all understand what is really going on. But Shire-folk have been so comfortable so long they don’t know what to do. They just want a match, though, and they’ll go up in fire."

_{- The Return of the King, Chapter 18: The Scouring of the Shire}

_{Credit for clarinets and matches to @Richard and his sockpuppet @Buffybot; permission has been given for me to copy this and the other answer will be deleted in 60 days. See chat here and here.}