Trigger mechanism

“ We may also occasionally wish to make connection to a trigger circuit in such a way that stimulus always changes the condition of the trigger circuit, either from stimulation to non-stimulation or vice-versa. ”

“ Ninety-five per cent. of the failures on the target range in the training camps come from not squeezing the trigger properly. You can't learn how to squeeze it on paper. You have got to practise. Every time you work your bolt, squeeze your trigger. ”

“ A sportsman, for example, pulls the trigger [Pg 52] of a gun, thereby initiating a long train of physical causes, which we may take up at the point where the powder is discharged, the shot propelled, and the bird dropped. Here the man's volition is supposed to have broken in upon the otherwise continuous stream of physical causes—first by modifying the molecular movements of his brain, so as to produce the particular co-ordination of neuro-muscular movement required to take accurate aim and to fire at the right moment ”

“ You need not use the trigger, nor even the cap; you may ignite powder in many ways. You may have many kinds of explosives. All that is essential is to have an explosion of a certain force and not too great rapidity. ”

“ The impulse generated can be made to pick up a thread, or pull a trigger, operate a trip hammer, blow up a mine or move a battleship or an ocean liner, given a strong enough lever. And that means simply a proper transformation of power or energy. ”

“ Deliberately prompt, up goes the fatal tube—even as the butt presses the shoulder, trigger is drawn after trigger. Bang! bang! the eye of faith and the finger of instinct have done their work, duly, truly. The thud of one bird, as he strikes the moist soil, tells that he has fallen ”

“ It would automatically prime itself again after firing. It would fire each time he pressed the trigger now, until it exhausted its projectiles.
Exultant, he laid it carefully in a contour chair, where it wouldn't slide out. ”

“ Consequently, a good single trigger is one that prevents this finger blow from discharging the second barrel. It is impossible to prevent the blow itself, but quite easy to prevent it letting off the second lock. ”

“ In an explosion there is usually something anterior to, or apart from, the explosive compound, that pulls the trigger, or touches the match, or completes the circuit, but in the slow and gentle explosions that keep the life machinery going, we cannot make such a distinction. ”

“ By practice the soldier becomes familiar with the trigger squeeze of his rifle, and knowing this, he is able to judge at any time, within limits, what additional pressure is required for its discharge. By constant repetition of this exercise he should be able finally to squeeze the trigger to a certain point beyond which the slightest movement will release the sear. ”

“ Now, take a steady aim, and the moment you have got the two sights in a line on the rock, press the trigger steadily. Press pretty hard; it is only a pull of about two pounds, but it is wonderful how stiff a trigger feels the first time you pull at it. You need not be at all afraid of the kick. If you press the butt tightly against your shoulder you will hardly feel it, for there is plenty of weight in the barr'l, and it carries but a small charge of powder. ”

“ Just as in the mechanism of a clock, so in the mechanism of the military machine, an impulse once given leads to the final result; and just as indifferently quiescent till the moment when motion is transmitted to them are the parts of the mechanism which the impulse has not yet reached. ”

“ But to come to a stop involved the jamming of myself, molecule by molecule, into whatever lay in my way; meant bringing my atoms into such intimate contact with those of the obstacle that a profound chemical reaction—possibly a far-reaching explosion—would result, and blow myself and my apparatus out of all possible dimensions—into the Unknown. This possibility had occurred to me again and again while I was making the machine; but then I had cheerfully accepted it as an unavoidable risk—one of the risks a man has got to take! ”

“ A trigger circuit, which is shown as an ellipse, differs from a limiting amplifier circuit in that once the inputs have reached the threshold so that it emits one pulse, it will continue to emit pulses until it receives an inhibitory stimulus. ”

“ Thus, as fast as the explosives are fired off by sense-stimuli, so fast in normal life are they reconstituted and the sensibility restored. Meanwhile the explosion at the end-organs has fired the train of explosives in the nerve, and created molecular explosive disturbances in the brain. Thence the explosive waves pass down other nerves to muscles or glands, and, giving rise therein to further explosions, take effect in the activities of the organism. ”

“ He showed that if a body like one of our minute oil drops is dancing about in a resisting medium subjected to no forces but those arising from its own energy of agitation, that is, from the bombardment of the surrounding molecules, the mean distance which it will drift in a given time, say ten seconds, from its position at the beginning of this time, can be computed in terms of three factors: (1) its energy of agitation, (3) a resistance factor of the medium, and (3) the length of the time interval through which the drift is observed. ”

“ The power of concentrating the mind and controlling the nerves and muscles by exercising the will are all developed by practice in trigger-pressing, and these qualities of character are essential for good shooting and for fire discipline.
3. Rules for Trigger-Pressing.— (i) The trigger of the S.M.L.E.rifle has a double pull-off, and two distinct pressures are necessary to fire the rifle. The first pull should be taken when the rifle has been brought into position for aiming; the second when the sights are aligned on the mark. The charger-loading Lee-Enfield rifle has a single pull-off. ”

“ This fact becomes still more evident when we discover how invariably response is increased by increasing the intensity of stimulus.
Electrical response is due, as we have seen, to a molecular disturbance, the stimulus causing a distortion from a position of equilibrium. In dealing with the subject of the relation between the disturbing force and the molecular effect it produces, it may be instructive to consider certain analogous physical phenomena in which molecular deflections are also produced by a distorting force. ”

“ When the molecules rebound, they are, as it were, driven away from the surface in virtue of the inherent elasticity both of the surface and of the molecules. Now, what takes place when one mass of matter is driven away from another—when a cannon-ball is driven out of a gun, for example? Why, the gun kicks! And so every surface from which molecules rebound must kick; and, if the velocity is not changed by the collision, one half of the pressure caused by the molecular bombardment is due to the recoil. ”

“ We perceive only what is nearest to us, namely, the scattered movements of the pulverized explosions. From them we have to go back, stage by stage, to the original movement.
When a shell bursts, the particular way it breaks is explained both by the explosive force of the powder it contains and by the resistance of the metal. So of the way life breaks into individuals and species. It depends, we think, on two series of causes: the resistance life meets from inert matter, and the explosive force—due to an unstable balance of tendencies—which life bears within itself. ”

“ Those, for example, on or near the external surface of the body—those, that is to say, which constitute the end-organs of the special senses—contain explosive material which may be fired by a touch, a sound, an odour, the contact with a sapid fluid or a ray of light. The effects of the explosions in these delicate cells, reinforced in certain neighbouring nerve-batteries, are transmitted down the nerves as waves of subtle chemical or electrolytic change, and thus reach that wonderful aggregation of organized and co-ordinated explosive cells, the brain. ”

“ Molecular energy, brought under control through the unstable equilibrium of certain artificial compounds, has given us the gun, the cannon, the bomb, the mine, and all the other infernal masterpieces of high explosives. ”

“ With regard to the second of the seven above-mentioned methods, we must especially observe, that compression and similar violence have a most powerful effect either in producing locomotion, and other motions of the same nature, as may be observed in engines and projectiles, or in destroying the organic body, and those qualities, which consist entirely in motion (for all life, and every description of flame and ignition are destroyed by compression, which also injures and deranges every machine) ”

“ How a gun shoots. Pulling a trigger makes a gun shoot by causing an explosion. There is a spring on the hammer of a gun. This drives the hammer down suddenly when you release the spring by pulling the trigger. The hammer jars the chemicals in the cap and causes them to explode. The heat and flame then cause the oxygen in the gunpowder to combine with some of the other elements in the powder to make a gas. The gas requires more room than the powder and is further expanded by the heat released by the chemical change. ”

“ The trigger stick a slips outside b, and the pressure holds the free stick c in place against the crotch. Bait is so placed on d that a bird coming to secure it must stand inside the slip noose which is spread on c. The weight and movement of the victim releases the trigger, draws the line taut, and closes the noose about its legs. ”

“ Each molecule contributes its quota to the latent electrical force, which shows up by explosion after its gathering in the storm clouds, and then it returns to the molecular embrace it originally occupied. ”

“ Our modern method of firing a gun is to place in close proximity with the gunpowder which we wish to decompose or explode, a small portion of fulminating powder, which is decomposed or exploded with extreme facility, and which, on decomposing, communicates the consequent molecular disturbance to the less-easily decomposed gunpowder. ”

“ After-oscillation.—In the case of the sensitive silver cell, we have seen (fig. 105) , when it has been subjected for some time to strong light, that the current of response attains a maximum, and that on the stoppage of the stimulus there is an immediate rebound towards recovery. In this rebound there may be an over-shooting of the equilibrium position, and an after-oscillation is thus produced. ”

“ In ballistics, again, we may measure the resistance which the medium in which we are obliged to operate, makes the force of impulsion and the target both obey the same law, and yield to the same process of calculation. ”

“ If, however the stimulus be not excessive and the impulse not too frequently evoked, the effect of a passage of an impulse once is to diminish the resistance, so that a second applica­tion of the stimulus provokes the reaction more easily, and he adds that the result of summation of stimuli is in fact in the direction of removal of block. When an impulse has passed once through a certain set of neurones to the exclusion of others it will tend, other things being equal, to take the same course on a future occasion, and each time it traverses this path the resistance in the path will be smaller. ”

“ Then, too, stimulated by these impressions, certain secretions are instantly emptied from the ductless glands into the blood which, acting like fuel in an engine, generate more power in the machine, fill it with anger or fear and prepare it to respond to the directions to fight or flee, or to any type of action incident to the machine. ”

“ Thus the dynamical energy of the medium applies the match, gives the turning-stroke to the pending explosion, and it is by this dynamical act that the specific chemical rupture is effected, in consequence of which the protoplasm reassumes its former contracted state in space. ”

“ I have shown in a former paper that the seat of sensitiveness is confined mainly to the surface layer of the sensitive substance, and that the nature of the substratum has little or no effect on the sensitiveness. Thus, a substance which exhibits a strong diminution of resistance, if coated with an extremely thin layer of a substance of the other class which shows an increase of resistance, will now exhibit an increase of resistance. It is seen that the action is one of the bounding layer or skin of the sensitive substance. ”

“ The form of the response curve, stimulus remaining constant, is modified by the molecular condition of the wire. A wire in a sluggish condition shows feeble response, the recovery being also slow. The same wire after it has been vibrated for a time exhibits a stronger response. Longer time is required for recovery from the action of a stronger stimulus. ”

“ But in certain cases we have the very remarkable phenomenon that a body acting as a catalyser is necessarily formed as a product, or bye-product, of the main reaction, and in such a case as this the reaction-velocity will tend to be steadily accelerated. Instead of dwindling away, the reaction will continue with an ever-increasing velocity: always subject to the reservation that limiting conditions will in time make themselves felt, such as a failure of some necessary ingredient, or a development of some substance which shall antagonise or finally destroy the original reaction. ”

“ In order to explain the phenomena of electric response, some physiologists assume that the negative response is due to a process of dissimilation, or breakdown, and the positive to a process of assimilation, or building up, of the tissue. The modified or positive response in nerve is thus held to be due to assimilation; after continuous stimulation, this process is supposed to be transformed into one of dissimilation, with the attendant negative response. ”

“ Even ground battles left few, since hand-held blasters at full power or molecular disruptors literally vaporized unarmored targets, and if enough of them overloaded an armored target's screen generator, the resulting explosion had the same practical effect. ”