An important part of an embryology project is letting the students see into the egg. It’s quite simple to do. You can purchase a candling unit that can do the job or you can make an inexpensive one yourself. You’ll need the following list of supplies:
- A tin can. This could be a coffee can or some similar metal can that has a removable top. A large size coffee can works better. try to find one with a bright shiny interior so that the light reflects better.
- A piece of wood to mount the can on. You can use and old scrap piece of 2″x6″ board. This will also give the candler a little weight to keep it from getting pushed around as the students push their eggs against it.
- A piece of foam or something similar to put around the hole where the egg touches to pad it a little. Don’t use black rubber since the black will come off on the egg!
- A lamp socket. You can either salvage one from an old lamp or purchase one at the store. It should be the type that can screw to the bottom of the coffee can.
- An electrical cord and wire. Either use some off an old lamp or purchase one at the hardware store.
- A switch. A simple on/off switch that costs about 89 cents at a hardware store will do fine.
- A 60 watt light bulb.
- A few small wood screws where required.
Procedure:
Drill small holes in the bottom of the can so that you can screw the lamp socket to the bottom, in the center. Next, drill a hole in the top and mount the on/off switch where it can easily be reached. Follow the instructions on how to hook up the cord to the light, then wire it in to the on/off switch. Drill a hole in the bottom of the can, near the bottom side and insert the cord with the plug on the end through, then connect it to the on/off switch. Although it is fairly simple to do, don’t be afraid to get a knowledgeable person to help you hook up the wires. Install a 60 watt light bulb in the socket.
Then, carefully use a scissors or metal cutter to cut a small circle in the lid. The hole should be only big enough for about 90% of the large end of the egg to poke through when held against it. Glue the piece of foam around the hole to serve as a pad. You could also use gray tape, almost anything will do as long as it provides a little padding. If you are using the plastic top off a coffee can, use black spray paint to coat the inside of the top so light won’t pass through.
Drill two small holes in the bottom of the can and use wood screws to fasten the can to the piece of wood. If you want, you can place a small block of wood between the can and the larger block to sort of put it on a pedestal. This may make it easy for the students to move their hand around as they hold the egg. A 60 watt build is usually sufficient. It will help if you turn out the lights in the room. If you use a bigger bulb, be sure that your socket and switches are rated for the higher wattage.
Sometimes, you can find old candlers at auctions and garage sales. Some of the antique ones like this one by Sears will work just fine if in good condition.
