What is the meaning of 'relative' and 'apparent' in Newton's concept of time?

[Aleoa]

In the masterpiece "Philosophiae Naturalis Principia Mathematica" , Newton says:

"Absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external, and by another name is called duration: relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time"

All this sentence seems clear to me, except the two adjective: relative and apparent. For you, what's is the meaning the Newton gives to this two adjectives in this context ?

 

[Orodruin]

He seems to be intending to distinguish ”mathematical time” and actual time measurements that act as observational placeholders. They would be relative in the sense that the precision of different instruments in finding a number corresponding to mathematical time might differ and apparent in that they are not actually the mathematical time but being used as a proxy.

 

[Dale]

All this sentence seems clear to me, except the two adjective: relative and apparent. For you, what's is the meaning the Newton gives to this two adjectives in this context ?

I wouldn’t spend too much effort on this. It is a translation of a very out of date document describing a concept that has been largely abandoned. It is only of historical interest.

 

[Aleoa]

He seems to be intending to distinguish ”mathematical time” and actual time measurements that act as observational placeholders. They would be relative in the sense that the precision of different instruments in finding a number corresponding to mathematical time might differ and apparent in that they are not actually the mathematical time but being used as a proxy.

Thanks. And the term "apparent" ?