"Of course we did, Harry, your mother was a Witch so you being a Wizard was very likely. We were simply waiting to see if you actually received the letter before we told you. If it didn't come then we didn't feel it needed to be brought up." Vernon informed his nephew with a sigh while Dudley sat in his chair looking back and forth between his parents and his cousin in shock and confusion. From there it was a conversation about the means to get in contact with Hogwarts and accept his invite to study there. Vernon and Petunia were uncomfortable around Magic and were hoping to have a staff member from Hogwarts take Harry to the Magical shopping center in London.
"It says they 'await my owl' what does that mean?" Harry asked confused as the letter had come through the normal post.
"Once you write your acceptance response there should be an owl perched somewhere near the house. Just hold it out to the bird and it should take it before flying back to them." Petunia informed remembering how Lily had sent her own acceptance letter back. With some help from Vernon and Petunia to make the acceptance letter at least partially formal, Harry sealed it up and headed out to the back yard. After looking around and not seeing an owl Harry got an idea.
"This could be a good time to try out my prototype." Harry mused to himself as he pulled his Magic Quantifier out of the waistband of his pants. "I really need to find a better place to keep this." He muttered before holding it against his head so that he could look through the lens of his trinket. A small bit of mana to the trinket and Harry started looking around the trees and even on rooftops within his line of sight. He didn't get any readings of mana as he looked around but surely an owl that delivered magical letters had to have some mana of its own, right? A sudden blip on the lens and the number '5' appeared causing Harry to stop his searching and notice an owl perched on the edge of the neighbor's fence with a tree branch shading its perch. It was no wonder he hadn't seen the bird. Its darker feathers and the shade it was perched in made it blend in. "Score one for my prototype though." Harry chuckled as he walked towards the owl slowly. 'At least I know I don't have to be aware of a Magical Being to get a reading on their mana.' He thought to himself as he stopped in front of the owl and held out the letter.
"Could you take my response back to Hogwarts?" Harry carefully asked the owl when it looked at him. There was something about the bird's eyes that led Harry to understand that the bird had more intelligence than normal. With a soft hoot the owl held out one of its legs. Harry noticed a piece of string tied around the leg and gently set about rolling his letter up and tying it to the owl's leg. With another hoot the owl took off and started flying in what Harry thought was a northern direction. "Guess I just wait now." He mumbled as he headed back inside. "Since my prototype works maybe I should come up with a name for it now? But what to call it, maybe I should use an acronym?" With a chuckle Harry walked back into the house and went up to his room to ponder names for his Magic Quantifier.
By the time next morning rolled around Harry had come up with a tentative acronym name he'd liked. Spell Crafted Ocular Unit Total Energy Reader or S.C.O.U.T.E.R. for short. Saying the full name was a mouthful but calling his Magic Quantifier a Scouter made some sense. Any Magical Being within thirty meters of Harry could have their total amount of mana 'scouted' by him so he would at least know their relative magical strength compared to his own. Plus he'd broken down his prototype's main features to come up with the words used in the acronym. Spell Crafted for how it was made, Ocular Unit because it was used by the eye, and Total Energy Reader because it told him the total amount of mana, which is what he called magical energy, a Magical Being had at their full strength. There were definitely still adjustments and improvements that could be made to his Scouter but for his first totally original design Harry felt that he'd done well.
A loud knock on the front door alerted everyone in the Dursley's home that someone had arrived. Harry made his way down stairs from his room only to see Vernon at the door looking gob smacked at the large, hairy man standing on his doorstep. This was probably the staff member from Hogwarts and Harry was already too curious to hold himself back. With a quick movement he had his Scouter at his eye and was scanning the huge man for his mana amount. Harry's eyes tried to follow the rapidly growing number on the lens but lost track quickly. When the number came to a stop Harry almost stumbled back in shock. There on the lens was the number '7,062'. Harry almost burst with questions just from the number alone. Was this an average reading for Magicals? Was it higher or lower than normal? How had the large man gotten such a high amount of mana? Why was he so large? Was it because he had so much mana? Question after question appeared in Harry's mind before he settled on a single realization to try and calm himself down. His '270' mana wasn't very much when compared to this man's. He'd need to look into becoming a bit more magically powerful in the future; it never hurt to be prepared after all. Quickly putting his Scouter back at his waist he walked down the stairs catching the large man's attention.
"There's Harry, look just like yer father, yeh do." The large man laughed as Harry came to stand beside Vernon.