Cute! I absolutely adore these two, so I'm glad I finally managed to find a fic of them. They're both in character, and I can definitely imagine this scene happening as one of their everyday lives. Just the usual antics with Escha, haha.

Though, the image of Logy having a tail...pfft. XD

Still fandomblind here...

So Escha has a magical (alchemical?) tail that her mother made and she's trying to figure out what makes it work?

Escha seems a bit overly optimistic... Logy is probably right to be worried about whether her experiment in recreating the tail will be dangerous.

String everywhere! :D

But we don't get to know whether she actually succeeded in making a tail or not... although I'm assuming not because of the string everywhere, Logy doesn't seem sure it was a failure in the last line, so I don't know.

I'm pretty sure that semi-colon is not used correctly and should be a comma instead. Other than that, I didn't spot any grammar issues. (Or I'm so used to your writing style by now that my brain just glosses over them... as sometimes happens.)

Well I wouldn't like to be the one that has to clean that mess up. I love how Logix is pretty unenthusiastic as he sits there watching Escha while she is so determined. It seems like he is getting a tail whether he likes it or not. My favourite part was when her concoction explodes and goes everywhere as you describe it really well.