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On the advantages of working engines with high pressure steam expansively, and at great velocities
~ ' l a l i t m . o f Rowan's fThurn.
S57
A rod with a slide in it and graduated like this rule, would, I think, be an improvement in the poles used for leveling ; the sights might then he directed, not to a graduation on the pole, but to a fixed object on the slide, specially designed for that purpose, and which might be elevated or depressed at pleasure, by a racked wheel, and its height seen by the intersection of the rod and its slide. Glasgow Prac. Mec.& Eng. Mag. "
On the Jldvantages of worMng Engines with High.pressure Steam expansively, and at great Velocities. B y $. G. BODM~R. The author based his observations upon the principle of a considerable area of piston being essential for taking advantage of the initiative impulse of highly elastic steam, in contradistinction to the idea of "a percussive action, which had some time ago found advocates.~
Prec. lns. Cir. Eng.
,
,~iemen's
London Atheneum.
Chronometrie Governor.
The action of this governor is so sensitive, that no variation of the speed of an engine, when 40 per cent. of its load is thrown off, can be observed, for the entire.change is performed in one-fiftieth of the revolution of the fly-wheel ; this change absorbs or adds a portion of the momentum of the pendulum, and slightly alters its arc of vibration, the limit of which is between lS ° ~nd 21°; and by the laws of pendulous motion, this is shown to effect the number of revolutions to the amount of' only 8 per cent. of its v~elocity, and even that small variation in the extreme position of the pendulum ceases immediately the momentum is restored to its former condition. Ibid.
Description of Rowan's Churn, as Manufactured by Ms. Ric~rAav RoniNsoN, Lisburn. k:ig. 1 represents the entire churn when set up for work: it consists of an oval-shaped vessel, divided, in the direction of its longest diameter, into two compartments ; in one of which the paddle-wheel works: in the other the butter is collected, as will be better understood by fig. 2, which is a section of it, viewed from above when the cover of the wheel is removed. By turning the paddle wheel (which resembles the one used in the old box-churn) a current of the milk is maintained in the direction of the arrows. As soon as the butter collects on the top of the milk, it is borne along with the current; and by sliding down the sluice (a) to the surface of the milk, the butter is intercepted, and accumulates on one side of the sluice ; it is then taken out with a small tin scoop, pierced with small holes, through which any milk may pass ; but perhaps the accompanying description which
S57
A rod with a slide in it and graduated like this rule, would, I think, be an improvement in the poles used for leveling ; the sights might then he directed, not to a graduation on the pole, but to a fixed object on the slide, specially designed for that purpose, and which might be elevated or depressed at pleasure, by a racked wheel, and its height seen by the intersection of the rod and its slide. Glasgow Prac. Mec.& Eng. Mag. "
On the Jldvantages of worMng Engines with High.pressure Steam expansively, and at great Velocities. B y $. G. BODM~R. The author based his observations upon the principle of a considerable area of piston being essential for taking advantage of the initiative impulse of highly elastic steam, in contradistinction to the idea of "a percussive action, which had some time ago found advocates.~
Prec. lns. Cir. Eng.
,
,~iemen's
London Atheneum.
Chronometrie Governor.
The action of this governor is so sensitive, that no variation of the speed of an engine, when 40 per cent. of its load is thrown off, can be observed, for the entire.change is performed in one-fiftieth of the revolution of the fly-wheel ; this change absorbs or adds a portion of the momentum of the pendulum, and slightly alters its arc of vibration, the limit of which is between lS ° ~nd 21°; and by the laws of pendulous motion, this is shown to effect the number of revolutions to the amount of' only 8 per cent. of its v~elocity, and even that small variation in the extreme position of the pendulum ceases immediately the momentum is restored to its former condition. Ibid.
Description of Rowan's Churn, as Manufactured by Ms. Ric~rAav RoniNsoN, Lisburn. k:ig. 1 represents the entire churn when set up for work: it consists of an oval-shaped vessel, divided, in the direction of its longest diameter, into two compartments ; in one of which the paddle-wheel works: in the other the butter is collected, as will be better understood by fig. 2, which is a section of it, viewed from above when the cover of the wheel is removed. By turning the paddle wheel (which resembles the one used in the old box-churn) a current of the milk is maintained in the direction of the arrows. As soon as the butter collects on the top of the milk, it is borne along with the current; and by sliding down the sluice (a) to the surface of the milk, the butter is intercepted, and accumulates on one side of the sluice ; it is then taken out with a small tin scoop, pierced with small holes, through which any milk may pass ; but perhaps the accompanying description which