Technology & Engineering Books

CHAPTER I Our object in reading and studying this book is to find out some facts that will help those of us who are thinking of going into farming and gardening as a business or recreation to start right, and will also help those of us that are already in the business to make our farms and gardens more productive. In order to make the book of greatest value to you, I would urge you not only to read and... more...

CHAPTER I INTRODUCTORY Fish culture of a certain kind dates from very early times, but its scientific development has only come about quite recently. Most people know that in our own country the monks had stew ponds, where they kept fish, principally carp, and also that the Romans kept fish in ponds. In the latter case we hear more often of the eel than of other fish. The breeding of trout and salmon,... more...

DESCRIPTIVE CATALOGUE OF PLANTS. 1. Abelmoschus moschatus.—This plant is a native of Bengal. Its seeds were formerly mixed with hair powder, and are still used to perfume pomatum. The Arabs mix them with their coffee berries. In the West Indies the bruised seeds, steeped in rum, are used, both externally and internally, as a cure for snake bites. 2. Abrus precatorius.—Wild liquorice. This twining,... more...

Depth of Soil for Fruit. Would four feet of good loose soil be enough for lemons? Four feet of good soil, providing the underlying strata are not charged with alkali, would give you a good growth of lemon trees if moisture was regularly present in about the right quantity, neither too much nor too little, and the temperature conditions were favorable to the success of this tree, which will not stand as... more...

Induction of Electric Currents. 6. About twenty-six feet of copper wire one twentieth of an inch in diameter were wound round a cylinder of wood as a helix, the different spires of which were prevented from touching by a thin interposed twine. This helix was covered with calico, and then a second wire applied in the same manner. In this way twelve helices were superposed, each containing an average... more...

INTRODUCTORY Electricity, like every science, presents two phases to the student, one belonging to a theoretical knowledge, and the other which pertains to the practical application of that knowledge. The boy is directly interested in the practical use which he can make of this wonderful phenomenon in nature. It is, in reality, the most successful avenue by which he may obtain the theory, for he learns... more...

FACTS AND OBSERVATIONS ON THE SALMON. In the following observations I intend to offer some remarks on the various migratory fish of the genus Salmo; and then some facts and opinions which tend to show the importance of some change in the laws which are now in force regarding them. We have first the Salmon; which, in the Ribble, varies in weight from five to thirty pounds. We never see the fish here... more...

CHAPTER I. THE APPARATUS. To a proper comprehension of the succeeding chapters, it is necessary first of all to be familiar with the apparatus employed in carrying out electro-balneological treatment, and I therefore proceed to give a description of this. It may conveniently be divided as follows, viz. a. The tub; b. The electrodes and connections; c. The water; d. Chemicals; e. The batteries. (a) The... more...

HOW NEWSPAPERS ARE MADE. We will suppose that it is a great newspaper, in a great city, printing daily 25,000, or more, copies. Here it is, with wide columns, with small, compact type, with very little space wasted in head lines, eight large pages of it, something like 100,000 words printed upon it, and sold for four cents—25,000 words for a cent. It is a great institution—a power greater than a... more...

THE MEN BEHIND THE MACHINES I MACHINES. AS SEEN FROM A MEADOW It would be difficult to find anything in the encyclopedia that would justify the claim that we are about to make, or anything in the dictionary. Even a poem—which is supposed to prove anything with a little of nothing—could hardly be found to prove it; but in this beginning hour of the twentieth century there are not a few of us—for... more...