Reading the journal will teach you Jard's secrets. Apparently, he really wasn't into explosives at all. You'll get the schematics for Pierre, the Rascal Bot, the Advanced Refrigeration Unit, and the Sky Claw when you learn the journal, as well as the item you'll need to make all of them -- Jard's Peculiar Energy Source. And this is where it gets a little frustrating, to say the least. Creating the energy source is easy, you only need 10 Ghost Iron Bars. What's frustrating is the cooldown -- you can only make one energy source per day. It's very much like the cooldown for Imperial Silk, except that there isn't an option to use Spirits of Harmony to bypass the cooldown at the present time.