Second.The steam establishes the greatest possible elasticity in the connection between a hammer and the driving power, and at the same time serves to cushion the blows at both the top and bottom of the stroke, or on the top only, as occasion may require.
The functions required in machinery for handling material in a machine shop correspond very nearly to those of the human hands. Nature in this, as in all other things, where a comparison is possible, has exceeded man in adaptation; in fact, we cannot conceive of anything more perfect than the human hands for handling materiala duty that forms a great share of all that we term labour."I fancy I can see a way out of the difficulty," he said. "I do not wish to pry into your affairs, but in a novelist's business one gets to know things. And I, too, am in a great quandary. Do you recollect the flower farm near Ajaccio?""Really if you will be guided by my opinion you will do nothing of the kind," he said, much as a magistrate might address a prisoner in the dock. "If you were called it would be a different matter. On the whole the best plan would be for you to be represented by a solicitor, who would put questions likely to--er--tell in your favour."There was a good deal of whispering and talking in corners and under the trees at Longmere House. A fussy little man with an eyeglass seemed to have a great deal to say. Lady Longmere laughed somewhat scornfully as she watched him. A great pile of strawberries were on her plate.There is, however, a principle in hydraulic machinery that must be taken into account, in comparing it with positively geared mechanism, which often leads to loss of power that in many cases will overbalance any gain derived from the peculiar action of hydraulic apparatus. I allude to the loss of power incident to dealing with an inelastic medium, where the amount of force expended is constant, regardless of the resistance offered. A hydraulic crane, for instance, consumes power in proportion to its movements, and not as the amount of duty performed; it takes the same quantity of water to fill the cylinders of such cranes, whether the water exert much or little force in moving the pistons. The difference between employing elastic mediums like air and steam, and an inelastic medium like water, for transmitting force in performing irregular duty, has been already alluded to, and forms a very interesting study for a student in mechanics, leading, as it does, to the solution of many problems concerning the use and effect of power.