Gilbert light experiments for boys . which falls on the lensis concentrated at thefocus. Repeat with the di-verging lens. Is thereno heat? ExperimentNo. 103. To light amatch with the sun is hotat mid-day put a Fig* 160, ^ou ^S^t a match with sunlight match on a piece of paper and focus sunlight on it with the short focus lens (Fig. 160).Does it light? Why? Experiment No. 104. Magic cannon. Repeat ExperimentNo. 59, but light the match by means of the short focus lens(Fig. 161). THE WHY OF IT When the parallel waves from the sun fall on a converginglens, which is thicker at the mid

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Gilbert light experiments for boys . which falls on the lensis concentrated at thefocus. Repeat with the di-verging lens. Is thereno heat? ExperimentNo. 103. To light amatch with the sun is hotat mid-day put a Fig* 160, ^ou ^S^t a match with sunlight match on a piece of paper and focus sunlight on it with the short focus lens (Fig. 160).Does it light? Why? Experiment No. 104. Magic cannon. Repeat ExperimentNo. 59, but light the match by means of the short focus lens(Fig. 161). THE WHY OF IT When the parallel waves from the sun fall on a converginglens, which is thicker at the middle than at the edges (Fig. 162), the portions of thewaves that go throughthe thick part areslowed up more thanthe portions which gothrough the thinnerparts, and as a resultthe waves are socurved in that theyconverge at the focusand diverge 161. You light the match in the bottle The waves are shown. 106 GILBERT BOY ENGINEERING

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Keywords: ., bookcentury1900, bookdecade1920, booksubjectscientificrecreation