Chapter XIII: Portable Acetylene Lamps and Plant

It will be apparent from what has been said in past chapters that the construction of a satisfactory generator for portable purposes must be a problem of considerable complexity. A fixed acetylene installation tends to work the more smoothly, and the gas evolved therefrom to burn the more pleasantly, the more technically perfect the various subsidiary items of the plant are; that is to say, the more thoroughly the acetylene is purified, dried, and delivered at a strictly constant pressure to the burners and stoves. Moreover, the efficient behaviour of the generator itself will depend more upon the mechanical excellence and solidity of its construction than (with one or two exceptions) upon the precise system to which it belongs. And, lastly, the installation will, broadly speaking, work the better, the larger the holder is in proportion to the demands ever made upon it; while that holder will perform the whole duty of a gasholder more effectually if it belongs to the rising variety than if it is a displacement holder. All these requirements of a good acetylene apparatus have to be sacrificed to a greater or less extent in portable generators; and since the sacrifice becomes more serious as the generator is made smaller and lighter in weight, it may be said in general terms that the smaller a portable (or, indeed, other) acetylene apparatus is, the less complete or permanent satisfaction will it give its user. Again, small portable apparatus are only needed to develop intensities of light insignificant in comparison with those which may easily be won from acetylene on a larger scale; they are therefore fitted with smaller burners, and those burners are not merely small in terms of consumption and illuminating power, but not infrequently are very badly constructed, and are relatively deficient in economy or duty. Thus any comparisons which may be made on lines similar to those adopted in