yup, I'm merely trying to get my head around how it works... making them is simple, but how they work..
but this -5volt swing has got me curious, i need an oscilloscope 
- thanks all, tomorrow i'll probe this circuit with my multimeter and give this relaxation oscillator / multivibrator / flip flop /astable osccilator / a good going over lol, i'll increase resistor and cap sizes and try and watch the voltages across the caps and bases of the transistor to see this in action, i built it, it worked i just have to slow it down..
p.s
if i see a yellow canary, it's a canary, if i see an orange canary, i don't start suddenly start calling the canary (even though it's a different colour) something else! (electronic engineers seem to do, 1 name is never enough)