S. E. Dowdy. M. P. S.

The microscope nowadays plays such an important part in scientific work that its claim to be called an instrument of precision and value is hardly likely to he disputed.

Microscopy as an intellectual pastime has, however, to a great extent been neglected for the, pursuit of other branches of natural science, and yet microscopy can lay claim to advantages not possessed to anything like the same extent by its rivals in the esteem of the youth of scientific proclivities.

In the first place, the instrument is comparatively inexpensive, it takes up little room, interesting objects are always available, and favorable conditions for viewing them are well within the observers control. Without wishing for one moment to disparage the pursuit of that branch of astronomy which particularly appeals to the amateur-viz., telescopic observation of stars, planets, and nebulae, can as much be truthfully claimed for the astronomical refractor or reflector? Of course, there is no reason why the two branches of science should not be taken up by the same person to advantage, the training to which the eye is subjected in microscopical work being conducive to more accurate observation of detail in astronomical work with the telescope; but if it is desired to keep to one subject, I for one do not think the beginner will be disappointed if he gives microscopy the preference. An erroneous impression no doubt exists that special skill and study are required, even if the microscope is to be used for recreation only. This is far from being the ease, as any intelligent person should be capable of deriving profitable amusement after a few hours possession of the instrument. At the same time no piece of apparatus requires more technical skill to handle it, if first-class results in critical research work are desired, and this in itself, by developing the individuality of the observer, constitutes one of the most forcible arguments in its favor from the educational point of view. Neatness, patience, dexterity in manipulation, are required of the successful microscopist, and the acquisition and cultivation of these qualities will fit him for success in other, perhaps widely different, spheres of activity.

Realising that it is frequently due to very hazy notions as to the cost, capabilities, and usefulness of the microscope, that many a wood-be microscopist is deterred from taking up this facinating study, with the Editor's kind permission, I propose to pen the following hints and suggestions for the use of those who are quite unacquainted with this branch of science. For this reason I have used the term "Microscopy for Amateurs " at the head of these communications. In the strict sense of the term, most of our leading micros-copists are amateurs, pure and simple. In this case the reader must take the word as synonymous with beginner. Starting with a few explanatory words regarding the early history of the instrument, we can then proceed to a brief description of a modern student's microscope, indicating how its lenses and adjustment may be tested, and pointing out a few common objects for early observations, with the hopes that any feeling of interest in the subject which may perchance be aroused may not be transient, but may lead to the formation of those habits of accurate observation which have in the past and will in the future do so much to enrich the sum of human knowledge.

The name of the first person who conceived the idea of enlarging the images of minute natural objects by means of lenses is unknown. The origin of the microscope is therefore still wrapped in obscurity, the credit of its invention being ascribed to first one individual and then another, as fresh evidence comes to light. Some claim the honor for Galileo, others for Janssen, a Dutch optician, though they are by no means the only candidates in the field. The probability is that in its simplest form, as a convex lens, it was known at a much earlier period ; possibly to the Romans or Egyptians. It is fairly safe to assume that the compound microscope was not known before the invention of the telescope, which probably preceded it; but the actual date of its origin, or the name of its originator, is a matter of doubt. At all events, it is a comparatively modern invention, taking the length of the civilized period of the earth's history as a standard. From a plaything for the scientists of the Middle Ages, it has won such recognition of its capabilities and adaptability that no modern laboratory, medical school, or similar scientific institution can dispense with its services.

Great simplicity of construction marked the earlier stages of the history of the microscope, the mechanical adjustments, as might be expected being crude in the extreme. This, however, was in keeping with its optical portion, which, owing to want of knowledge of the laws of light and methods of giving the necessary curvatures to the lenses, was, of course, defective. This fact probably induced the great naturalist, Leenwen-hoek, to discard the compound for the simpler microscope, which could at that time be relied upon to give more faithful images. The possibilities of the compound instrument were, however, not lost sight of, and we find various modifications introduced from time to time, until about the year 1800 it began to assume much the general outline with which we are now familiar. It was also about this time that the optical portion was receiving increased attention, and though the theory of the achromatism of lenses was imperfectly understood, we find attempts being made to give the necessary correction to the objectives, so that clearer images might be obtained. To enter fully into details concerning the evolution of the modern microscope would fill a fair-sized volume, a few lines cannot do justice to it.

To those interested in the subject, a perusal of that part of "Carpenter on the Microscope " devoted so the history of the instrument will show that the modern instrument is the result of much patient work, with which the names of many famous men of science have been connected. Of late years strenuous efforts have been made to incorporate the results of the latest researches in certain branches of chemistry and mathematics in the preparation of glass and the figuring of lenses, with the result that a first-class modern microscope is a triumph both for theoretical and applied science. What is still more important to the amateur, though, is the fact that, through increased interest in the subject and competition amongst readers, a really excellent microscope can now be obtained at a very low cost. After the purchase of such an instrument; a very small additional outlay will enable the beginner to do good work with it ; or if recreation be the end in view, many pleasant hours may be spent in its company, and a first-hand acquaintance with some of Nature's minute marvels be made; an acquaintance which, in the majority of cases will deepen the wish for a more intimate knowledge of the subject.

The history of lead pencil making goes back three or four hundred years. The lead pencil derives its name from the fact that before the time when pencils were made from graphite, metallic lead was employed for the purpose. Graphite was first used in pencils after the discovery, in 1565, of the famous Cumberland mine. This graphite was of remarkable purity, and could be used without further treatment by cutting it into thin slabs, and encasing them in wood. For two centuries England enjoyed practically a monopoly of the lead pencil industry. In the eighteenth century, however, the lead pencil industry had found its way into Germany. In 1761, Caspar Faber, in the village of Stein, near the ancient city of Nuremburg, Bavaria, started in a modest way the manufacture of lead pencils, and Nuremburg became and remained the centre of the lead pencil industry for more than a century. For five generations Faber's decendants made lead pencils. Up to the present day they have continued to devote their interest and energy to the development and perfection of pencil making. Eberhard Faber, a great-grandson of Caspar Faber, emigrated to the United States, and, in 1849, established himself in New York City. In 1861 he erected his pencil factory in New York, and thus became the pioneer of the lead pencil industry in the United States. Since then four other firms have established pencil factories there. Wages, as compared with those paid in Germany, were very high, and Eberhard Faber realized the necessity for creating labor-saving machinery to overcome this handicap. Many automatic machines were invented, which greatly simplified the methods of pencil making, and improved the product.