The Put-Outer and Magic on Privet Drive
Dumbledore's Put-Outer is a magical device introduced in PS1, and it is unique as the only tool used to perform magic aside from wands. The Put-Outer also has the distinction of being the first magical tool introduced in the series:
[Dumbledore] found what he was looking for in his inside pocket. It seemed to be a silver cigarette lighter. He flicked it open, held it up in the air, and clicked it. The nearest street lamp went out with a little pop. He clicked it again - the next lamp flickered into darkness. Twelve times he clicked the Put-Outer, until the only lights left on the whole street were two tiny pinpricks in the distance, which were the eyes of the cat watching him. If anyone looked out of their window now, even beady-eyed Mrs. Dursley, they wouldn't be able to see anything that was happening down on the pavement. Dumbledore slipped the Put-Outer back inside his cloak and set off down the street toward number four, where he sat down on the wall next to the cat (PS1).
The Put-Outer raises a number of questions. Why does Dumbledore use a Put-Outer to extinguish the street lamps rather than simply using his wand? Is there something preventing Dumbledore from using his wand? Does JKR introduce the Put-Outer in PS1 because she does not yet wish to tell the reader about magic? Why does JKR, a master of inventing clever names like "Pensieve" and "Veritaserum", choose a conventional name like Put-Outer? Why has there been no mention of the Put-Outer since the opening chapter of the series?
Based on what we have been told, it is conceivable that the Put-Outer is a clue about the protections surrounding Harry when he is in the care of his relations. After all, a powerful wizard like Dumbledore probably could have used his wand to extinguish the street lamps. Lupin and Harry both light lamps at Hogwarts with their wands, and Trelawney dimmed the lights in her classroom with a wave of her wand (PA12, GF29).
Nevertheless, Dumbledore appears to extinguish the lamps with the Put-Outer and then simply re-ignite them. Or does he? Compare the above quoted passage involving use of the Put-Outer to extinguish the lamps with the description of how Dumbledore restores the street lamps:
On the corner, he stopped and took out the silver Put-Outer. He clicked it once, and twelve balls of light sped back to their street lamps so that Privet Drive glowed suddenly orange and he could make out a tabby cat slinking around the corner at the other end of the street (PS1).
When Dumbledore extinguishes the lamps, they just go out, and balls of light do not fly from the lamps into the Put-Outer. But when he turns them on, they don't just pop back on. Instead, balls of light come out of the Put-Outer and go into the street lamps. Dumbledore may be doing much more than adjusting the lighting. He may be putting something important from the Put-Outer into the street lamps, and it could be related to the protection for Privet Drive.
JKR, of course, wants to keep all of this a mystery at this point in the series. So she it appears that she misdirects the reader in three ways. First, she writes that "twelve balls of light sped back to their street lamps." Of course, we can now see that these twelve balls of light never went from the street lamps into the Put-Outer in the first place. The phrase "back to their street lamps" encourages the reader to conclude that these are the same twelve balls of light that Dumbledore extinguished, but they probably are not.
Moreover, in giving the device the name "Put-Outer," JKR did not concoct a clever name. Instead, she seems to have selected a painfully obvious name to further convince the reader that Dumbledore really is just turning the lamps off and on. Also, after JKR describes the balls of lights speeding back to the lamps, she immediately brings up the tabby cat to shift the reader's attention away from the street lamps.
Could it be that JKR simply chose the name Put-Outer for other reasons, such as a desire not to reveal immediately that the books involve magic? Perhaps. If that is the case, however, it is difficult to square this with the other obvious clues in PS1 indicating the presence of magic. After all, Hagrid arrives on "a huge motorcycle [that] fell out of the air" (PS1). Dumbledore consults his magical watch: "It had twelve hands but no numbers; instead, little planets were moving around the edge" (PS1). Had JKR wished to delay the introduction of magic until later in PS, this scene could have been written to conceal entirely the presence of something magical.
It is also possible that Dumbledore does not use his wand because his wand will not work on an electric street lamp. We certainly know that the reverse is true: Hermione explains that electrical devices will not work in the magical world of Hogwarts (GF28). In CS, however, Arthur Weasley is able to bewitch the Flying Ford Anglia, which undoubtedly has electrical systems (CS3). That indicates that wizards can bewitch and control electrical devices, suggesting that the electricity in the lamps does not preclude the use of a wand or necessitate the use of a Put-Outer.
* * * * * * * *
"But how to get at Harry Potter? For he has been better protected than I think even he knows, protected in ways devised by Dumbledore long ago, when it fell to him to arrange the boy's future. Dumbledore invoked an ancient magic, to ensure the boy's protection as long as he is in his relations' care. Not even I can touch him there" (GF33).
If the Put-Outer is accomplishing something more than extinguishing and igniting the street lamps, what could that be? It is possible that the Put-Outer established part of Harry's protection on Privet Drive.
There are at least two possible protections associated with the balls of light that Dumbledore may have placed in the street lamps. One possibility is that the Put-Outer rendered the Dursleys' home Unplottable or invisible. The trouble with the idea of Unplottability or invisibility, however, is that Fred, George and Ron are able to find the Dursley house in a flying car, Dobby finds it, and Mr. Weasley connects it to the Floo network (CS2, CS3, GF3). That suggests that the protection surrounding Harry is not some form of Unplottability or invisibility.
A more likely possibility is that the Put-Outer and balls of light are some form of surveillance system that lets The Ministry of Magic and Dumbledore know what happens on Privet Drive. Indeed, there could be a connection between the twelve balls of light that speed to the street lamps and the twelve planets in Dumbledore's magical watch.
The possibility of a magical surveillance system explains several instances in which the Ministry of Magic immediately learns about magic on Privet Drive. The Ministry of Magic responds immediately to Dobby's magic and the blowing up of Aunt Marge. Dumbledore knows that Harry isn't receiving his letters, that Harry is moved from the cupboard to the bedroom, and that the Dursleys and Harry flee Privet Drive (PS3, CS2, PA3). The existence of a surveillance system would also explain Fudge's knowledge and concern when Harry fled Privet Drive in PA. Harry was outside of his relations' care and a few streets away on Magnolia Crescent when he hailed the Knight Bus. It is understandable that Fudge was very concerned -- the Ministry of Magic could no longer see Harry, and The Ministry of Magic had no means of protecting him because Harry was "off the radar."