This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
One of the most distressing sides of botanical study is the short life of the colors in flowers. Those who have found the usual method of preserving plants by pressure between paper unsatisfactory will be interested to learn of a treatment whereby many kinds of flowers may be dried so that they retain a great deal of their natural form and color.
Ill: Placing the Flowers on the Steel Pins and Pouring the Dry Sand around Them
The flowers should be gathered as soon as the blossoms have fully opened. It is important that they should be quite dry, and in order to free them of drops of rain or dew, they may be suspended with heads downward for a few hours in a warm place. It is well to begin with some simple form of flower.
A large, strongly made wooden box - one of tin is better - will be necessary, together with a sufficient amount of sand to fill it. If possible, the sand should be of the kind known as "silver sand," which is very fine. The best that can be procured will be found far from clean, and it must, therefore, be thoroughly washed. The sand should be poured into a bowl of clean water. Much of the dirt will float on the surface. This is skimmed off and thrown away, and clean water added. The sand should be washed in this manner at least a dozen times, or until nothing remains but pure white grains of sand. The clean sand is spread out to dry on a cloth in a thin layer. When thoroughly dry, it should be placed in a heavy earthenware vessel and further dried in a hot oven. Allow it to remain in the oven for some time until it is completely warmed through so that one can scarcely hold the bare hands in it.
Obtain a piece of heavy cardboard and cut it to fit easily in the bottom of the box. Through the bottom of the cardboard insert a number of steel pins, one for each of the flowers to be preserved. Take the dry blossoms and press the stalk of each on a steel pin so that it is held in an upright position. When the cardboard is thus filled, place it in the box.
The warm sand is put in a bag or some other receptacle from which it can be easily poured. Pour the sand into the box gently, allowing it to trickle slowly in so that it spreads evenly. Keep on pouring sand until the heads of the flowers are reached, taking care that all of them stand in a vertical position. The utmost care must be taken, when the heads are reached, to see that all the petals are in their right order. Remember that any crumpled flowers will be pressed into any position they may assume by the weight of the sand. When the box is filled it should be covered and set aside in a dry place.
Ill: The Dried Flowers
The box should be allowed to stand at least 48 hours. After the first day, if only a small amount of sand has been used, the material may have cooled off to some extent, and the box must be set in a moderately heated oven for a short time, but no great amount of warmth is advisable. After 48 hours the box may be uncovered and the sand carefully poured off. As the flowers are now in a very brittle condition, any rough handling will cause serious damage. When all the