allowed to remain there for a short time, and then withdrawn as quickly as possible. As soon as we begin to withdraw this instrument, the valves close, and consequently include a quantity of water from the lowest level, at which it has been.

"We have used the above described instrument on many different occasions, and in many different Artesian Wells, both those of recent and of several years' formation, and on no occasion did we find the slightest difference of temperature between the water taken at the mouth of the bore and that brought up by the instrument."

Railway Reports.

Ibid.

The report presented to the proprietors of the London and Birmingham Railway, at the late half-yearly meeting, contains several statements of a highly satisfactory nature, to which we may here briefly advert, as all other companies must look with interest to the results afforded by this magnificent and ably-conducted undertaking. The directors remark that the receipts for passengers have been advancing steadily since the early part of the year; and it appears that the total number conveyed by the railway, for the six months, has been 267,527-the daily average for the whole length of the line having been 857. The revenue for the halt-year amounted to 270,814l.; the charges upon this sum, including interest on loans, and a reservation of 14,000/. for depreciation of stock, was 165,684/., leaving an available balance of clear profit (including a surplus of 70831. from the previous half-year), amounting to 112,2131. It was recommended by the directors that a dividend of 31. 10s. per 100l. share (7 per cent. per annum), and amounting to 109,375l., should be declared; and the report was, of course, carried unanimously, having evidently produced feelings of satisfaction in every proprietor present.

Improvement in Railway Carriages.

Mining Jour.

On Wednesday, a lecture was delivered at the theatre of the Mechanics' Institution, on a new description of railway carriages, invented by Mr. Coles of Charing-cross, and for which he has obtained a patent. The value of the invention was noticed in the Mining Journal at the time it was first made public, and by the working models exhibited, every statement formerly made was fully borne out. The improvement is, in the first place, by the addition of anti-friction wheels, which lessens the propelling power to one-eighth of that used by common carriages. Manual labour may be substituted for steam, and an increased speed is obtained; besides these advantages, the axles are formed on a safety principle, so that no irregularity of the railroad, or sudden curve, will cause the vehicle to run off, the axles working perpendicularly, horizontally, or obliquely, according to the position in which the vehicle may be accidentally thrown. Several eminent engineers were present, and gave their full approbation to the invention, and there is no doubt that in a short time the improved carriages will be used on the railroads.

NOTICE.

A Meteorological Journal for the year 1839, has been received from an anonymous correspondent at Pittsburg. It appears to have been kept with care, and the Committee on Publications will be happy to insert it in the general report, if they are furnished with the name of the observer.

Angles reckoned to the right or

LUNAR OCCULTATIONS FOR PHILADELPHIA, westward round the circle, asseen

in an inverting telescope.
Fordirectvision add 180°

Maximum heightduring the month. 58.00

Barometer. 30.15 on the 27th. 23.80 " 28th. 29.73

JOURNAL

OF THE

FRANKLIN INSTITUTE

OF THE

State of Pennsylvania,

AND

MECHANICS' REGISTER.

APRIL, 1840.

Practical and Theoretical Mechanics and Chemistry.

FOR THE JOURNAL OF THE FRANKLIN INSTITUTE.

Remarks on the Combustion of Charcoal in close rooms, and its deleterious

Effects.

The frequent occurrence of fatal accidents, from the combustion of charcoal in close apartments, and the apparent prevalence of the idea, that a deleterious action on the animal system is is peculiar to that kind of fuel, has induced me to offer, through the pages of the Journal, a few remarks intended to give a correct notion of the subject, in a popular form.

Every one who has given any attention to his own sensations of existence. is doubtless aware, that life is continued by the act of breathing. This operation is carried on by the muscular action of the chest; whereby a portion of air is drawn into the lungs, and again expelled, after imparting to the blood through the tissues of the lungs a portion of one of its constituents. The constituent which is the useful agent in this process, is termed by chemists oxygen, and sometimes vital air, it forms one fifth part of the atmosphere; the other four fifths being azote or nitrogen, with a small admixture of other gases. The oxygen alone, is necessary for respiration, the azote serving merely to dilute and diminish the activity of the vital air. By a process not yet clearly explained, oxygen imparts to the blood a renewed fitness for the maintainance of life, and is essentially necessary for that purpose; if an animal is deprived of oxygen for a short time it dies. Death by drowning is occasioned by the exclusion of oxygen from the lungs by the water, and may be produced by immersing the mouth and nostrils only; thus a man may be drowned in a single gallon of water.

This brief sketch of the process of respiration may serve to render intelVOL. XXV.-No. 4, APRIL 1840.

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