THREE:Boring, as distinguished from drilling, consists in turning out annular holes to true dimensions, while the term drilling is applied to perforating or sinking holes in solid material. In boring, tools are guided by axial support independent of the [137] bearing of their edges on the material, while in drilling, the cutting edges are guided and supported mainly from their contact with and bearing on the material drilled.
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Lorem ipsum dolor sit amet, consectetur adipisicing elit. Aliquam aut tenetur, amet earum quia eligendi obcaecati. Repudiandae id illum, vero iste enim reprehenderit quaerat, harum pariatur ipsa nulla tempora ex ratione illo assumenda libero ea, delectus vitae, expedita optio porro.
ONE:Dick, who had caught up Larrys abandoned binoculars, saw as they zoomed and climbed that a sailor had rescued the note before it bounded over the cabin roof and deck into the sea.I had a short chat with the wounded men near the various houses, on demand showed my passport to those in authority, and was advised as a friendly Netherlander to return, as it was extremely dangerous on the road. But I did not dream of doing34 this, as long as I was not compelled, and went on towards Lige amidst this maddening thunder.
ONE:VI.I returned with two large round "brown Georges"soldiers' loaves.
ONE:If asked for advice as to the most important object for an apprentice to aim at in beginning his fitting course, nine out of ten experienced men will say, "to do work well." As power is measured by force and velocity, work is measured by the two conditions of skill and time. The first consideration being, how well a thing may be done, and secondly, in how short a time may it be performed; the skill spent on a piece of work is the measure of its worth; if work is badly executed, it makes no difference how short the time of performance has been; this can add nothing to the value of what is done although the expense is diminished.Another principle in planing machines which deserves notice is the manner of driving carriages or platens; this is usually performed by means of spur wheels and a rack. A rack movement is smooth enough, and effective enough so far as a mechanical connection between the driving gearing and a platen, but there is a difficulty met with from the torsion and elasticity of cross-shafts and a train of reducing gearing. In all other machines for metal cutting, it has been a studied object to have the supports for both the tools and the material as rigid as possible; but in the common type of planing machines, such as have rack and pinion movement, there is a controversion of this principle, inasmuch as a train of wheels and several cross-shafts constitute a very effective spring between the driving power and the point of cutting, a matter that is easily proved by planing across the teeth of a rack, or the threads of a screw, on a machine arranged with spur wheels and the ordinary reducing gearing. It is true the inertia of a platen is interposed and in a measure overcomes this elasticity, but in no degree that amounts to a remedy.
