Materials needed:
* Two round glass lenses of different focal lengths
* A metal or plastic frame
* Small screws or rivets
Instructions:
1. Cut the two lenses to the same size and shape.
2. Attach one lens to the top half of the frame and the other lens to the bottom half.
3. Use small screws or rivets to secure the lenses in place.
2. Lightning Rod:
Materials needed:
* A metal rod (copper or aluminum)
* A metal ball or point
* A wooden pole
* Ground wire
Instructions:
1. Attach the metal ball or point to the top of the metal rod.
2. Connect the ground wire to the bottom of the metal rod.
3. Mount the metal rod on the wooden pole and secure it in place.
3. Pennsylvania Fireplace:
Materials needed:
* Fireplace grate
* Cast iron stove
* Fire bricks
* Mortar
Instructions:
1. Build a fireplace grate and place it in the fireplace opening.
2. Install the cast iron stove on top of the fireplace grate.
3. Surround the cast iron stove with fire bricks.
4. Use mortar to seal the joints between the fire bricks.
5. Flexible Catheter:
Materials needed:
* Silver cannula
* Brass tube
* Lead weight
Instructions:
1. Insert the silver cannula into the brass tube.
2. Secure the cannula in place with a lead weight.
3. Use the flexible catheter to insert the cannula into the urethra.