thank you for your opinion theoristjoey,
now, here is how your wrong:
Time IS infinite in both directions, that is it has no begining or end. however, it does not take the form of a loop, it is linear. and yes, you could use a time machine to travel back to 1820. you would simply need to set it to take you back 134 years, and viola, you would be in 1820. however, making a trip back through time 134 years in a single leap would result in you ending up in an alternate world line with such a divergence from your own, you might not recognize it as being 1820. you would be better off making the trip in a series of smaller jumps.