quantity of pig iron made, or capable of being made, at the present time (by the furnaces in blast,) being 1,327,612 tons per annum, from which, however, we may deduct 20 per cent.-leaving 1,062,090 tons as the actual make. On comparing this statement with an abstract of the quantity of pig iron estimated to have been manufactured in the year 1839, and which is embodied in Mr. David Mushet's work, entitled Papers on Iron and Steel, we find the average weekly make at that period to have been as follows:

or an annual make of 1,248,260, which is called in Mr. Mushet's work 1,248,781 tons. It will be thus seen, that, comparing the present make with that of the average of 1839, the number of furnaces in that year was 429, of which 379 were in blast; whereas, in February, 1842, the number had increased to 527, of which only 350 were in work, the majority being at a reduced make of 25 per cent.-the aggregate quantity made weekly being, in 1839, 24,005 tons, and in February, 1842, 25,531 tons there being an increase, in the past two years, of 98 furnaces, equal to an additional make of 407,680 tons per annum (about one-third the average make,) while the number of furnaces in blast in 1839 was greater than those enumerated as being in operation at the present time.

We do not propose entering further into the subject, but having collected that information, which is not only interesting, but valuable, as statistical detail, we leave to our correspondents to furnish such additional particulars as they may possess, having, so far as lies in our power, devoted our attention to the subject.

Mining Jour., March, 1842.

Rise. P. M. Rise P.M. Direction.

70° 879 29.90 29.90 SW.

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76 29.90 29.85 SE. SW.

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JOURNAL

OF

THE FRANKLIN INSTITUTE

OF THE

State of Pennsylvania,

AND

AMERICAN REPERTORY.

NOVEMBER, 1842.

Civil Engineering.

FOR THE JOURNAL OF THE FRANKLIN INSTITUTE.

Remarks on Reaction Water Wheels used in the United States; and on the Turbine of M. Fourneyron, an Hydraulic Motor, recently used with the greatest success on the continent of Europe. By ELLWOOD MORRIS, Civil Engineer.

[CONCLUDED FROM PAGE 227.]

On Turbine Water Wheels.-Having completed our remarks upon reaction water wheels, by endeavouring to show that they are not superior in effect to undershot wheels, unless when acting in backwater; we will now proceed to consider the turbine of M. Fourneyron, which-whether employed upon falls as low as three feet, or as high as 354 feet-whether immersed in backwater or not-realizes continually, with remarkable uniformity, a proportion of useful effect quite as great, in comparison with a given power expended, as can be obtained from the best overshot wheels, working under the most favorable circumstances; in other words, whilst the co-efficient of effect belonging to the turbines, continually approximates to 0.800, it remains nearly invariable, under all circumstances of fall and position; this peculiar wheel possessing the remarkable property of being equally effective and suitable, in almost every situation where water wheels can be used as motors.

The turbine, or water wheel invented by M. Fourneyron, is like

VOL. IV, 3RD SERIES.-No. 5.-NOVEMBER, 1842.

25

the reaction wheel, formed of cast iron, (often in a single piece,) and like it, is usually made to revolve horizontally about a vertical axis.

In the following sketches, c c represents a horizontal section of the wheel rotating in the direction of the arrow, about a vertical axis passing through a pipe attached to the fixed disk d d; which disk is surmounted by a series of guides, curved in a particular manner, whereby the water is conducted to the wheel, made to issue tangentially, and press upon the curved buckets perpendicularly, or nearly so, thus producing a revolving motion.

The admission of water from the upper level to act upon the wheel, is regulated by an annular sluice gate, which envelopes the curved guides, and shuts down upon the fixed disk; when this sluice gate is raised, the water issues out between the curved guides and turns the wheel; when closed, a water tight joint is formed, and none can pass to the lower level; all which will be easily comprehended, from an examination of the following description and diagrams.

Fig. I exhibits part of a horizontal section of a turbine; in which ccc shows the wheel turning in the direction of the arrows; d d, the fixed disk, with its curved guides attached, the spaces between which are the sluices whence the water issues, and presses upon the curved buckets of the wheel; g, the shaft pipe, which sustains the fixed disk in an unchangeable position upon its lower extremity, and is itself

sustained at its upper end by the carpentry above the forebay; through this pipe the shaft of the wheel h rises to communicate motion to the works driven by the turbine; the open annular space between d and c represents the place of the sluice gate, which is a short portion of a thin hollow cylinder of cast iron, moving vertically, in contact with the fixed cylinder n n, at its upper part, and closing down water tight upon the fixed disk; wooden blocks are screwed upon the inside of the annular sluice gate, which slip between the curved guides and are rounded above and below, in order to improve the ajutage, and thus facilitate the efflux of the water, as is more clearly seen at fand e, Fig. II.

Fig. II.

Fig. II exhibits a vertical section of a turbine; a a, the surface of water in the upper level, or forebay; b b, the surface of water in the lower level, or tail race; c c, the wheel with buckets curved in plan; dd, the fixed disk and curved guides firmly supported by the shaft pipe g; e e, the annular sluice gate, with its wooden internal cushions ff, to improve the ajutage; g g, the shaft pipe; h, the shaft upon which the wheel c c is firmly fixed at its lower part, so as to carry the shaft with it in its movement of rotation; this shaft runs upon a suita