t The progress of trees is sometimes greatly retarded by But Calculations, shewing every fourth year from 12 to 64, the progressive annual increase in the growth of trees, and the gradual decrease in the rate per cent. per annum that the annual increase bears to the whole tree. The whole height of the trees is taken to the top of the leading shoot, and the girt in the middle; but no account is taken of the lateral branches. If trees increase eighteen inches in height, and two inches in circumference, annually, their increase will be as undermentioned, viz. Explanation of the Construction of Tables I and II. To render the preceding tables easy to be understood by persons not accustomed to calculations, I will state the process of the operations in the first line of Table II. The The height of the tree at 12 years of age is supposed to be 18 feet to the top of its leading shoot, and 24 inches in circumference at the ground, consequently at half the height, the circumference is 12 inches, one fourth of this, being three inches, is called the girt. The girt being squared and multiplied into the height, gives one foot one inch and six parts for its contents. At 13 years old the tree will be 19 feet high, 26 inches in circumference at the ground, and 13 inches at half the height; one-fourth of 13 gives 34 inch for the girt. This squared and multiplied into the height, gives one foot five inches and one part for the contents. Deduct from this the contents of the tree at 12 years of age, and there remains three inches and seven parts, which is the increase in the 13th year. Then reduce the contents of the tree when 12 years old, year, each into parts, dividing the former by the latter and the quotient will be 3.76; by this number divide 100, and the quotient is 26.5. which is the rate per cent. of increase made in the thirteenth year; consequently whatever the tree might be worth when 12 years old, it will, at the end of the 13th year, be improved in value after the rate of 267. 10s. per cent. or in other words, that will be the interest it will have paid that year, for the money the tree was worth the preceding year. and the increase in the 13th At every succeeding period, both in this Table and Table I. the like process is gone through. Observations on Tables I. and II. The preceding tables furnish us with the following useful information, viz. 1st. That all regular growing trees, measured as above, as often as their age is increased one-fourth, contain very nearly double their quantity of timber. 2nd. That when a tree has doubled its age, its contents will be eight-fold. 3d. That when a tree has doubled the age, its annual growth will be increased four-fold. 4th. Consequently that when a tree has doubled its age, the proportion that its annual increase bears to the contents of the whole tree, is then diminished one-half. This last observation explains how it comes to pass that a tree, when its age is doubled, the rate per cent. per annum that its increase then bears to the content of the whole tree, is diminished one-half. It may not be unuseful to observe, that the rate per cent. of increase in the last columns, is the same as the rate per cent. that the increase of the tree that year will pay for the money it was worth the preceding year. In the two preceding tables, we find that the rate of increase per cent. per annum is the same in both at the same ages, although the quantity of timber in the second table is six times as much as in the first table in trees of all ages; therefore, when the age of a tree is known, the rate per cent. per annum of its increase is known on inspecting these tables, whether the tree has grown fast or slow; provided the growth of the tree has been regular, and that it has continued its usual growth. And having the age, girt, and height of any tree given, we can readily calculate what quantity of timber it will contain at any future period whilst it continues its usual rate of growth. TO BE CONTINUED IN OUR NEXT. Method Method of Stabbing Hoven Cattle to discharge the rarified Air from the Stomach, when they have been over-fed with moist Clover Grass. By Mr. W. WALLIS MASON, of Goodrest Lodge, near Warwick. With Engravings. From the TRANSACTIONS of the SOCIETY for the Encouragement of ARTS, MANUFACTURES, and COMMERCE, The Silver Medal was voted to Mr. MASON for this Communication. I BEG leave to lay before you a trocar and canula, for the relief of cattle when gorged or hoven. Since I have introduced it, it has been used with the greatest success, having, in every instance tried, been proved a safe, easy, and effectual remedy. I consider it will not be necessary for me to detail the dangerous consequences arising from cattle being hoven, as it is well known that the public are annually deprived of numbers of valuable cattle by this disorder. I am inclined to offer it as an instrument superior to that for which the Society granted a premium in the year 1796, as I am of opinion that flexible tubes may be forced down the ventricle which conducts to the lungs, by which most dangerous consequences would ensue. instance of this kind occurred last year in this neighbourhood, when intending to force the passage of the paunch, and occasioned the loss of the animal. An Neither the farmer or bailiff can be expected, when going the rounds of the farm, to carry with him at all times an instrument so large as one of the flexible tubes; even if he had it, he could not make use of it without the the assistance of a second person, and the disorder would be fatal in most instances before such assistance could be procured. I considered that the trocar and canula, commonly used by surgeons, might be employed to advantage for the relief of hoven cattle. I have improved the instrument, to answer better the purpose here intended of penetrating the tense hides of cattle; and such alteration materially facilitates the operation. The method of applying it is, to penetrate with the trocar and canula through the hide of the beast, to the paunch on the near side, about six inches from the. back-bone, at an equal distance from the last rib, and from the hip-bone; then to withdraw the trocar, and to leave the canula in the wound, until the air which the paunch contained has escaped. The canula may then be taken out, and the wound covered with a plaster of common pitch, spread on brown paper, about the size of a crown piece. All the danger incidental to the common mode of stabbing with the knife is effectually prevented, by the canula being left in the incision when the trocar is withdrawn. The small expense of the instrument, its portability, the ease with which it can be used by an individual, its safety and efficacy in use, as it has not in any instance failed of complete success, will, I hope, be sufficiently evident to recommend it to the attention of the Society. A great saving would arise to the owners of cattle, and to the country at large, from general adoption of its use. A feeding ox will thrive as well after the operation as if it had never been affected by the disorder. Cows in calf are in no danger from its use. It has been found |
