The pressure gauge fell with astonishing rapidity, despite the minuteness of the aperture; and in a few minutes indicated about 24 barometrical inches.

I cannot bring my report to a conclusion without recording my acknowledgments to Mr. James Roe for the able and effective assistance he has rendered me throughout the expedition, the barometrical observations and management of the provision department having been especially under his charge.

All our booksalmost every record of the journeyour journals and registers of astronomical and barometrical observationshad been lost in a moment, But it was no time to indulge in regrets; and I immediately set about endeavoring to save something from the wreck.

Favored beyond our expectations, all our registers had been recovered, with the exception of one of my journals, which contained the notes and incidents of travel, and topographical descriptions, a number of scattered astronomical observations, principally meridian altitudes of the sun, and our barometrical register west of Laramie.

Fortunately, our other journals contained duplicates of the most important barometrical observations.

The following is an epitome of the yearly meteorological report for 1867, for which I am indebted to Professor Dove: Barometrical readings.

In 1867 the difference between the highest and lowest barometrical readings was not more than 13.96 millimetres, and would have been much less if the mercury had not been much depressed by storms in July and September.

According to my own barometrical reading, the height of the summit above the level of the sea was twenty-three hundred and seventy-four meters, or eighty-five hundred and fifty-nine Spanish feet.

We arrived in the evening at the southern point of the crater's edge (1,041 meters above the level of the sea by my barometrical observation), where a deep defile prevented our further progress.

Barometrical observations were made as often as necessary for giving a profile of the route from the head of Halls Stream to Arnold or the Chaudiere River, and thence to Lake Magaumac via the corner of the State of New Hampshire.

Some further barometrical observations were made between the lake and the Kennebec road, but for a portion of that distance the barometer was unserviceable in consequence of air having entered the tube.

Barometrical observations for comparison were made at the intersection of the Kennebec road and height of land hourly from 7 a.m. to 5 p.m. while the parties were on the dividing ridge.

Barometrical observations show its altitude, above the same point, to be 1,680 feetwhich denotes an average descent of a fraction over six inches per mile.

At Potosí the boiling-point is still lower, being 188°, and the barometrical column stands at 18°.

The barometrical column ranged between 29.75 and 30.22 inches; a fall of the mercury preceded a westerly wind, and a rise predicted it from the South-East: when it stood at thirty inches we had sea-breezes from south with fine weather.

During the time this magical appearance continued, we had very light airs from the southward: the barometrical column fell to 29.76 inches, but the hygrometer indicated an extraordinary dryness of the air.

In the two cases given, if the change of weather follows immediately the movement of the barometrical column, that change will last only a very short time.

In winter, after a frost of some duration, a rapid falling of the barometrical column announces a change of wind, accompanied by a thaw and rain; but a rising which happens during a frost which has already lasted a certain time, prognosticates snow.

Now, just toward the 20th of February, the oscillations of the barometrical column began to preoccupy the young novice, who noted them several times a day with much care.

All the time the mercury continued to fall in the barometrical tube, and, on this last day, the novice noted that it kept continually below twenty-eight and seven-tenths inches.

Besides the barometrical column fell again almost immediately, and nothing could inspire any hope of the end of that bad weather within a short period.

The next day, March 27th, the column of mercury rose in the barometrical tube.

The wind kept in the condition of a stiff breeze all the time, and certain oscillations of the barometrical column indicated that it tended to freshen.

We halted at the Pass of the Curral, to which Captain Stanley's barometrical observations* assign an elevation of 2700 feet above the sea.

Captain Stanley's azimuth and altitude observations, taken at two stations at the base, the distance between having been measured by the micrometer, give its height as 1,161 feet; and Lieutenant Dayman's barometrical measurement makes it 1,151 feet, above the sea level.)