Ev 1117: Metre Cube By Oxymoron

[DocHH]

Hello Evers,
As soon as I saw this week's setter I rather sensed a rather loud sigh of resignation from Devadolly in the NW! However I found the clue-ing very fair and quite quickly populated the Eastern side of the grid. The proliferation of a particular letter there guided me to what needed to be highlighted, as did the maths! It then aided me with populating the SW segment. The NW segment was the last to be completed, but by that time the Title had shed all the light neccessary!
Time for a preprandial!

[novalis]

Hi DocHH

Eastern half done during breaks from work but struggling on eastern half. Will have another look later.

[jim360]

Well done you.

[devadolly]

OK Clevercloggsis! Yes DocHH there was an almighty groan when I read the title..........MATHS, then the sight of the author illicited a dropping of the head in the hands. Have done quite well considering my 'relationship' with Mr O but have no doubt I will be whineing to you kind people for help by Wednesday. Even worse, a reliable source tells me that Kcit is one of the next to be published........oh woe!

[AHearer]

I did rather wonder whether this had been left over from January 2012....

[Jogler]

Oops. We seem to have 11 very plausible clashes.

[crockshard]

...and I have 12 and haven't even finished the top half yet...

[DocHH]

Welcome Crockshard, and welcome back Jogler(s),
All the clashes are within the peripheral lights, hope that helps with both the clashes and the reverse entries.

[DocHH]

I havejust realised that my last post could be miscontrued. There are not any clashes in the peripheral lights, is probably a better way of expressing what I meant! Mea Culpa!

[crockshard]

That is very helpful, DocHH. I will now amend the one I have in 1a and 46a!

[bambi123]

An extremely enjoyable puzzle. I suspect that the extraneous clashes above were caused by incorrect lights - I had an alternative answer for 24 which threw me for a while.
Very satisfying once all the pennies fell into place including the symbolism of the highlighted cells
Think this is the first Oxymoron I have completed so look forward to further puzzles from this compiler.

[novalis]

Managed to complete it slowly but surely between bits of work.

[crockshard]

This is my first attempt at an EV. I thought I was doing okay, but I just can't get a cubic centimetre, let alone a cubic metre, into the NE corner.
In 7d, whatever can '250 seconds' be, and what are '300 tons' in 13d???

[novalis]

Crockshard, 7 d definition is runs through. The medieval Roman numeral for 250 is E and seconds give s. What is inside them is an anagram. 13 down - The medieval Roman numeral for 300 is B. The support is something which golfers use + T for tons. There is a misprint in the definition.

[crockshard]

Thankyou, Novalis. I will get started again now!

[crockshard]

Whew! Finished!