This apparatus was set up for two weeks. The first week the table contained fine, white sand and the second week it contained fuel pellets. Fuel pellets changed the type of play in the table. The children could no longer use funnels like they did with the sand, but they could do other things. One thing the fuel pellets encouraged was more role play, such as cooking. One of the other discovered activities was plugging the tubes at the bottom.
One boy figured out that one of the measuring cups fit nicely into the bottom of the plastic tube.
Yep, it's plugged.
Because I observed this child plugging the tube, I was able to use this same provocation with children in other classes. In one of the classes while a child's parents were in the room, I plugged the tube right before the child poured the pellets into the tube. I asked the child "Where did the pellets go?" She had observed before that they emptied through the tube into the table, but now she couldn't figure out where the pellets went. She poured a second time and looked for the pellets emptying into the table. In the meantime, her parents picked up the questioning. The father said he could see the wheels turning in his daughter's head trying to figure out where the pellets were going. The child figured it out in short order without help. The parents and their child then took the activity to another level. They decided to see if they could plug all the tubes and fill them all up. That interaction between the parents and their child was an extra validation for this activity on this particular day.
One of the added advantages to building an apparatus for the sensory table is that the apparatus creates spaces to play and explore that are extraneous to the apparatus itself. For example, here are two children who are playing at the table but not with the apparatus.
One child is busy carefully filling a measuring cup while the other child is emptying it. (It is a curious interaction because they appear to working at opposites harmoniously.) They are both operating next to the apparatus, but not using it at all. You may think that this play could happen even without the apparatus. Yes it could have, but the apparatus is still creating another space in the table that is not part of the apparatus. Just look at the vertical plane of the box next to the two children. It is not an enclosure, but it is still an area created by being "next to" the apparatus.
Here is another example.
Oscar is operating on the end of the table where the apparatus does not extend. He is making soup---green soup to be exact. He is making it to pour it out. Again, this play could have happened without the apparatus, but the space created next to the apparatus enhances his focus.
I have known for many years that just changing the material in the sand table changes the play and exploration. I am now beginning to realize that an apparatus creates spaces extraneous to the apparatus itself. Children will find those spaces and use them in their play and exploration. In fact, they are so good at it they will find spaces that I had no idea existed.