Go over to the left side of the helmet. Insert rivet in the missing spot. Slide the rivet and open the the panel. Get a model acorn. Turn the switch underneath. A compartment will open. Grab the wooden model piece.
Go back to the helmet. Notice strange symbols on the inside of panel door similar to the one on metal plate. Insert the metal pointer and use the X shaped dial to operate the barometer. A copper tap will appear. Grab the copper tap.
Go back to the stone circle. Exam the metal acorn. Turn the top part to open the acorn revealing a key underneath. Then place the metal acorn on the tree image. Turn the dial to open the door. Insert the antler. Adjust the left antler to mirror image the right antler. The top part of the box will lifted revealing a stone mortar. Place the crystal phial in the center. Get a glowing gemstone.
Place the illuminated lamp inside the lantern. Obtain an engraved pyramid. You have complete Chapter 2.