In 1623 Ursinus published Rhabdologia Neperiana at Berlin, and the rods or bones were described in several other works.
With respect to the calculating rods, he mentions in the dedication that they had already found so much favour as to be almost in common use, and even to have been carried to foreign countries; and that he has been advised to publish his little work relating to their mechanism and use, lest they should be put forth in some one else's name.
The figures as written down are 12510 6255 14595 1534560 Napier's rods or bones consist of ten oblong pieces of wood or other material with square ends.
The arrangement of the numbers on the rods will be evident from fig.
The set of ten rods is thus equivalent to four sets of slips as described above, and by their means we may multiply every number less than II,irr, and also any number (consisting of course FIG.
Of course two sets of rods may be used, and by their means we may multiply every number less than 111,111,111 and so on.
It will be noticed that the rods only give the multiples of the number which is to be multiplied, or of the divisor when they are used for division, and it is evident that they would be of little use to any one who knew the multiplication table as far as 9 X9.
In multiplications or divisions of any length it is generally convenient to begin by forming a table of the first nine multiples of the multiplicand or divisor, and Napier's bones at best merely provide such a table, and in an incomplete form, for the additions of the two figures in the same parallelogram have to be performed each time the rods are used.
Napier also describes in the Rabdologia two other larger rods to facilitate the extraction of square and cube FIG.
In the Rabdologia the rods are called "virgulae," b'ut in the passage quoted above from the manuscript on arithmetic they are referred to as "bones" (ossa).
Besides the logarithms and the calculating rods or bones, Napier's name is attached to certain rules and formulae in spherical trigonometry.
This simple form of crane thus embodies the essential elements of foundation, post, framework, jib, tie-rods and gearing.
It consists essentially of a jib made of single I-sections, and supported by tie-rods (fig.
A and A' carry two light vertical rods S, M, the one as much in front of the other as there is space between two successive holes in the perforated ribbon.
To the other ends of A, A', rods H, H' are loosely hinged, their ends passing loosely through holes in the end of the bar L.
The operation is as follows: the paper ribbon or perforated slip is moved forward by its centre row of holes at the proper speed above the upper ends of the rods S, M; should there be no holes in the ribbon then the cranks A, A' will remain stationary, although the beam B continues to rock, since the rods S, M are pressing against the ribbon and cannot rise.
Ordinary indifferent cells of the epithelium containing pigment-granules, and (2) visual cells, slender sensory epithelial cells of the usual type, which may develop visual cones or rods at their free extremity.
In the red variety of Cucurbita pepo these crystals may consist of rods, thin plates, flat ribbons or spirals.
6); and it has been suggested that the association of these two is analogous to the association of the rods and cones of the animal eye with their pigment layer, the light absorbed by the red pigment-spot setting up changes which react upon the refractive granule and being transmitted to the flagellum bring about those modifications in its vibrations by which the direction of movement of the organism is regulated.
In the retina the cones prevail in numbers over the rods, as in the mammals, and their tips contain, as in other Sauropsida, coloured drops of oil, mostly red or yellow.
Rules drafted by the Board of Trade under this act came into force on the 8th of August 1902, the subjects referred to being (I) labelling of wagons; (2) movements of wagons by propping and tow-roping; (3) power-brakes on engines; (4) lighting of stations and sidings; (g) protection of points, rods, &c.; (6) construction and protection of gauge-glasses; (7) arrangement of tool-boxes, &c., on engines; (8) provision of brake-vans for trains upon running lines beyond the limits of stations; (9) protection to permanent-way men when relaying or repairing permanent way.
In shunting yards the points are commonly set in the required direction by means of hand levers placed close beside the lines, but those at junctions and those which give access from the main lines to sidings at wayside stations are worked by a system of rods from the signal cabin, or by electric or pneumatic power controlled from it and interlocked with the signals (see Signal: § Railway).
A highand low-pressure cylinder are cast together, and the piston-rods belonging to them are both coupled to one cross-head which is connected to the driving-wheels, these again being coupled to other wheels in the usual way.
In this engine the two piston-rods of one side are not coupled to a common cross-head, but drive on separate cranks at an angle of 180°, the pair of 180° cranks on each side being placed at right angles.
The advantages claimed for it are: short coupling-rods, large and unlimited fire-box carried by a trailing axle, compactness, and great power for a given weight.
My house was on the side of a hill, immediately on the edge of the larger wood, in the midst of a young forest of pitch pines and hickories, and half a dozen rods from the pond, to which a narrow footpath led down the hill.
The Fitchburg Railroad touches the pond about a hundred rods south of where I dwell.
Nay, I was frequently notified of the passage of a traveller along the highway sixty rods off by the scent of his pipe.
There the sun lighted me to hoe beans, pacing slowly backward and forward over that yellow gravelly upland, between the long green rows, fifteen rods, the one end terminating in a shrub oak copse where I could rest in the shade, the other in a blackberry field where the green berries deepened their tints by the time I had made another bout.
Once, in the winter, many years ago, when I had been cutting holes through the ice in order to catch pickerel, as I stepped ashore I tossed my axe back on to the ice, but, as if some evil genius had directed it, it slid four or five rods directly into one of the holes, where the water was twenty-five feet deep.
There is a narrow sand-bar running into it, with very deep water on one side, on which I helped boil a kettle of chowder, some six rods from the main shore, about the year 1824, which it has not been possible to do for twenty-five years; and, on the other hand, my friends used to listen with incredulity when I told them, that a few years later I was accustomed to fish from a boat in a secluded cove in the woods, fifteen rods from the only shore they knew, which place was long since converted into a meadow.
It is wonderful with what elaborateness this simple fact is advertised--this piscine murder will out--and from my distant perch I distinguish the circling undulations when they are half a dozen rods in diameter.
As near as he could remember, it stood twelve or fifteen rods from the shore, where the water was thirty or forty feet deep.
As I was paddling along the north shore one very calm October afternoon, for such days especially they settle on to the lakes, like the milkweed down, having looked in vain over the pond for a loon, suddenly one, sailing out from the shore toward the middle a few rods in front of me, set up his wild laugh and betrayed himself.
He dived again, but I miscalculated the direction he would take, and we were fifty rods apart when he came to the surface this time, for I had helped to widen the interval; and again he laughed long and loud, and with more reason than before.
He manoeuvred so cunningly that I could not get within half a dozen rods of him.
At length having come up fifty rods off, he uttered one of those prolonged howls, as if calling on the god of loons to aid him, and immediately there came a wind from the east and rippled the surface, and filled the whole air with misty rain, and I was impressed as if it were the prayer of the loon answered, and his god was angry with me; and so I left him disappearing far away on the tumultuous surface.
Sometimes, however, he will run upon a wall many rods, and then leap off far to one side, and he appears to know that water will not retain his scent.
He would perhaps have placed alder branches over the narrow holes in the ice, which were four or five rods apart and an equal distance from the shore, and having fastened the end of the line to a stick to prevent its being pulled through, have passed the slack line over a twig of the alder, a foot or more above the ice, and tied a dry oak leaf to it, which, being pulled down, would show when he had a bite.
When I had mapped the pond by the scale of ten rods to an inch, and put down the soundings, more than a hundred in all, I observed this remarkable coincidence.
A thermometer thrust into the middle of Walden on the 6th of March, 1847, stood at 32º, or freezing point; near the shore at 33º; in the middle of Flint's Pond, the same day, at 32º; at a dozen rods from the shore, in shallow water, under ice a foot thick, at 36º.
One pleasant morning after a cold night, February 24th, 1850, having gone to Flint's Pond to spend the day, I noticed with surprise, that when I struck the ice with the head of my axe, it resounded like a gong for many rods around, or as if I had struck on a tight drum-head.
The ice was melted for three or four rods from the shore, and there was a smooth and warm sheet of water, with a muddy bottom, such as the ducks love, within, and he thought it likely that some would be along pretty soon.
There is a canal two rods wide along the northerly and westerly sides, and wider still at the east end.
In the morning I watched the geese from the door through the mist, sailing in the middle of the pond, fifty rods off, so large and tumultuous that Walden appeared like an artificial pond for their amusement.