OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure


    

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure


    

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

     OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure


    

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure

      

   OPTICS
 --------------
   - bottle
   - straw
   - gum
   - 2 clothes pins

   - cloth grating in holder 
   - pin (stuck in side)
   - tape measure