I have a Meade ETX90 which is very similar. Considering the ease of use, portability ect, it has been a very instructive and enjoyable scope. You can also easily and cheaply add USB camera to do imaging with a computer...
Dynamo in the US is an outdated term that used to mean generator and/or alternator not sure which. I was wondering if dynamo might just be Aussie for motor in the US?
What I believe that mfb is trying to say is that angular diameter, unless otherwise stated, is taken to be the angle formed between two lines whose meeting point is at the observer and whose ends fall on opposite sides of the object being measured.
The fourth spatial dimension could for example be orthogonal, at right angles to, to all three of the dimensions we are so familiar with. All three, simultaneously...
It is labeled with 'R' so I would assume so. I agree that this looks like a resettable counter but couldn't it also be a four line multiplexer? A little bit of context would help.
This is very important. Oxygen can be extremely toxic. If the partial pressure of oxygen in any breathable gas mix at depth exceeds one atmosphere, seizures and death may occur even before drowning.
http://en.wikipedia.org/wiki/Oxygen_toxicity as a start.
Prickly lips sounds like nitrogen...