The Machine

"Finally, it's finished!" I exclaimed as I put the finishing touch on my machine, "There is only one thing to decide now, whether or not to share to this discovery. If I share it I call sell it, but everyone would be changing the past. I could keep it a secret, making no money, but I would become very powerful. I would be able to know what would happen; all I would have to do is not die. I would be the world's greatest hero, or the world's greatest villain. All of this from a small stopwatch is my pocket! Amazing!" Walking over to my calculations I thought about what to do next. "Yep, these are right. I can go back any time! Now to go back to stop World War I." I set the time back three months eight days, and 100 years. I pressed the the button I installed on the back and instantly I was covered in a veil of white light. I then passed out as an effect of the strain of time travel. When I awoke I realized that I could see myself tinkering at my workbench. I must not have gone back as far as thought I would take me. I wonder where my calculations went wrong. I have to sneak out of here before I am noticed, but first to take a picture of the calculations. CLICK. Crap, forgot to take the flash off.
"What was that?" I heard my other self mumble to himself without looking up from his work. I look around for a way out, I see that the garage door to my left. I start crawling toward the door, careful not to touch anything. I see my self get up, I stop dead in my tracks as he leaves. When he closes the door behind him I make a run for it. I make it out just as he re-enters the room. Taking out my phone to look at the picture to see where I went wrong to notice that I forgot to carry the one on the second equation. That means that I can only go back two days at a time. Now not knowing what to do I started to walk down the street.
"Hey, Jim," I hear my neighbor say to me, "I see that you gave up stupid idea that you could build a time machine." About to yell at him to say that he is wrong I remember that he is about to die of a heart attack.
"Hold on a sec, I have to call 911" I respond.
"Why?" He replies unaware.
"911, what is your emergency?" I hear through the phone.
"Could I have the medics? Someone is having a heart attack." I say calmly.
"Are you sure?"
"Yes."
"Alright, the medics have been dispatched."
I look over to my neighbor I see him clutching his chest. 'Looks like I have done my part here,' I thought as I walked away briskly.