The smock mill Goliath in front of the wind farm Growind in Eemshaven in the Netherlands. A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain (gristmills), pump water (windpumps), or both.
When bat guano is harvested, it is in a powdered form. Plants that can benefit from the use of bat guano fertilizer include vegetables, herbs, ornamentals, and fruit and nut trees.
1 Use a large lathe (a machine that spins wood) to test the batâs balance. Align the center of the bat blank with the drive center on the lathe. The bat should spin smoothly. If it spins out of control, the bat is out of balance and you must repeat step four.  Sculpt the Bat.