Fig. 121. the uncanny wheel
How to Make Carbon Dioxide Gas.
—Take a perfectly dry bottle or flask of the kind shown in the [fountain experiment]; fit it with a single hole stopper and push a glass tube through it until it nearly touches the bottom as pictured at [B].
Set the bottle at a slant and put a mixture in it of equal amounts of powdered copper oxide (that is cupric oxide) and wood charcoal. Heat this mixture over a Bunsen burner until it glows and for a few minutes longer; the bottle will then be full of the carbon dioxide gas.
Pour it into a glass pitcher and put a sheet of glass over it to keep the air away from it until you are ready to perform the uncanny experiment.
Giving a Travelogue.
—A travelogue is simply a talk on travel, or on a country, illustrated with pictures of some kind.
To be able to give a travel talk does not mean necessarily that you must have traveled or been in the country you are going to tell about but if you have done neither, it does mean that you must read up on it.
To do this get several good books on whatever country you intend to talk on, read them carefully, and then outline a route just as though you had gone over it yourself, but this must of course conform to the pictures you can get.
Now there are four methods you can follow to show a series of pictures and you can make your choice according to the amount of money you want to invest in it.