HE PANAMA CANAL.-The Panama Star Hand Herald of February 3rd, says: "On Saturday afternoon, January 29, 1881, the French steamer Lafayette arrived at Colon with MM. Armand Reclus, G. Blanchet, and about forty other gentlemen, who are to be employed on the Panama Canal. For the present, and it is presumed permanently, the Canal headquarters will be in Panama, although Colon will be the main point for dis tribution of supplies, &c., for the work. The expedition is divided into two distinct sections or departments. M. Reclus is the general agent, with full powers from the Canal Company over all matters which may require his attention and decision on the isthmus. M. G. Blanchet is director of the canal works. It is understood that the work of the various sections and commissions is to be begun at once and pushed on with energy. It will relate principally to the exact location of the line for the proposed canal, clearing away the timber, brush, &c., thus opening up the country through which the excavation will be made; arranging matters of titles for right of way, buildings, &c., and the general land grants of the company, and other matters of a preliminary character which must necessarily precede the commencement of the actual work. A year or more must necessarily elapse before the employment of machinery will be necessary or possible, and in the meantime the number of laborers which will be needed will be comparatively small. The demand can be easily supplied at present, or for some time to come, on the isthmus or in the near neighborhood, and any great immigration of mere bone and muscle seeking employment in ordinary canal work is, for the present, unnecessary."

RAILWAY NOTES.

THE FIRST RACK RAILWAY IN PRUSSIA.--BY

THE lead and silver

mines of the Friedrichshagen Consolidated Company of Oberlahnstein are situated between Ems and Lahnstein, about 11⁄2 mile from the banks of the Lahn. The company employs nearly one thousand work people, male and female, and in 1878 raised 14,000 tons of ore, which had to be transported at the rate of 46 tons a day down the valley to the river, there to be conveyed in barges to its destination. The system of land carriage being no longer equal to the requirements of the mine, it was determined to make a private railway on the Riggenback system. The line, which was opened on the 8th of November, 1880, is partly ordinary and partly rack railway. The difference of level between the two termini is 384 feet, which had to be surmounted in a length of 8,200 feet, thus giving 1 in 24.4 as the mean gradient. The steepest part worked by adhesion is 1 in 20.5, and by the rack rail 1 in 10. The racked portion is altogether 1,968 feet long, divided into three inclines of respectively 262, 1,165, and 541 feet each. The width of

on the racked portions are everywhere of a radius of 475 feet. At both ends, and at the middle of the line for the dressing floors, are sidings reached by switches of the ordinary construction, and a turntable affords access to the tracks laid in the works below. The teeth of the rack are 3.9 inches from center to center; it weighs 90 lbs. per yard, and cost about 228. per yard at the works. The rails, 34 inches high, weigh 50 lbs. per yard, and cost £8 108. per (metric) ton. In spite of the generally economical nature of the line, it was impossible to avoid some heavy works in cuttings and banks, the excavation in rock amounting to more than 15,000 cubic yards. It was also necessary to cross the line of the Nassau railway, the many streams in the valley, and the road leading to the Friedrichshagen works. Some of the bridges are of iron, but the greater part are of masonry. The working stock is at present limited to one locomotive and eighteen wagons. The engine, constructed in the works of the Swiss central railway at Olten, weighs 10 tons, or with fuel and water, 11.8 tons, and cost £1,120.

Its load is 10 tons up to the mine, and 18 tons down to the valley. The wagons weigh 0.9 ton each, and carry 2.5 tons. They are provided with brakes, and cost £32 108. each. The greatest speed is six miles an hour. The line was begun in April, 1880, and was only seven months in making. It cost, including working stock, 150,000 marks (£7,500) or 60,000 marks per kilometer (£4,800 per mile), which compares favorably with similar lines in Switzerland, costing from 140,000 to 97,000 marks per kilometer. This makes the tenth railway in Europe on the Riggenbach system, the others being at Arth Rigi, Vitznau-Rigi, Rohrschach-Heiden, and quarry lines at Ostermundingen and Laufen, and the Ruti line in Switzerland; Kahlenberg, and Schabenberg in Austria-Hungaria; and the Wasseralfingen line in Wurtemburg.- Wochenblatt für Architekten und Ingenieure.

ORDNANCE AND NAVAL.

HE NEW ARMORED CRUISER. - Active Tmeasures are being taken at Portsmouth for commencing the new armor-clad cruiser mentioned in the Navy Estimates for 1881-2. She will be constructed in No. 12 dock, within the extension works, a plan of building which has many advantages over the method usually adopted of building on a slip. All the weights, instead of having to be raised, will be dropped to where they are wanted, and when the ship is completed she will be simply floated out of dock, instead of having to be launched into the water by the expensive and complicated method adopted in the case of the Inflexible. The only drawback is the exposure to the weather, and this will be remedied by some temporary shelter. The length of the ship has been increased to 315 feet between perpendiculars, while her breadth is 61 feet, and her mean draught 24 feet 3 inches. About 120 tons of material, consisting of angle

THE

HE GAS ENGINEER'S DIARY AND TEXT BOOK FOR 1881. By G. E. Wright and Wm. S. Mason. Birmingham: Office of "Gas Engineer. For sale by D. Van Nostrand. Price $1.00.

The portion of this work which is termed the "Literary Section " will probably prove to be the valuable portion to gas engineers on this side of the Atlantic. This section is com

posed of several articles by different writers, specially prepared for this work and devoted to gas engineering and gas manufacture A portion of the work is devoted to tables, formulas and statistics of special use to the working engineer.

II. Wave Action.

III. Currents and Scour.

IV. Dublin Bar.

V. Dublin Harbor Improvement
Schemes.

VI. Dublin Bar-Treatment by Induced Tidal Scour. The illustrations, twenty-three in number, are good.

HE COAL FIELDS OF GREAT BRITAN. By Edward Stanford. For sale by D. Van Nostrand. Price $6.40.

This is of local rather than general interest. The descriptions of the geography and geology of the coal districts are exceedingly full and the maps are very fine.

A brief sketch of the coal fields of India

and of North and South America closes the volume.

A

TECHNICAL TREATISE ON SOAP AND CANDLES, WITH A GLANCE AT THE INDUSTRY OF FATS AND OILS. By R. S. Cristiani. Philadelphia: Henry Carey Baird & Co. For sale by D. Van Nostrand. Price $6.00.

In this, as in all complete works on subjects relating to chemical technology, the chemical and physical properties of all the raw materials are fully discussed, and as in this case the number of substances is considerable, a large space is devoted to the natural history of an interesting class of bodies, which will render the book of value to many who are not interested in the processes of manufacture, to which the volume is otherwise devoted.

The illustrations are numerous and good, and serve to describe with great minuteness the latest improved methods.

IM
MAGINARY QUANTITIES, THEIR GEOMETRI-
CAL INTEPRETATION.
the French of M. Argand. By Prof. A. S.
Translated from
Hardy. For sale by D. Van Nostrand. Price

50 cents.

This essay forms No. 52 of the Science Series, and is presented just as it appeared in the pages of this magazine.

It is of the class of essays which most students, who take delight in mathematics, will read with pleasure and profit. It will interest

more readers than do the heavier articles of the mathematical journals, inasmuch as the subject is one presented to the student almost at the beginning of his algebra.

The notes of the translator will, we think, be read with quite as much interest and profit as the original essay.

SYNOPSIS OF THE FRESH-WATER RHIZOPODS. Compiled by Romyn Hitchcock, F. R. M. S. New York: Romyn Hitchcock. For sale by D. Van Nostrand. Price 75 cents.

This is practically a descriptive catalogue of this interesting group of Protozoa. The characteristics of the genera are given with satisfactory fullness; then follows a list of species with the principal features described, after each is described great minuteness.

The book will prove a great aid to students who collect microscopic organisms, and, indeed, is calculated to stimulate many to begin

such work.

E'

LECTRIC LIGHTING BY INCANDESCENCE, AND ITS APPLICATION TO INTERIOR ILLUMINATION. With 96 illustrations. By William Edward Sawyer. 8vo. New York: D. Van Nostrand. 1881. Price 2.50.

This is a book of great practical value to all who wish to understand the subject. The style is exceptionally clear and comprehensive. We, of course, perfectly understand that the book is written in order to introduce the Sawyer system of lighting to the general public; therefore, the closing words of the preface, implicitly carried out as they are throughout the whole book, appear noble by comparison with many books of the same order. We quote: "Those who expect to find them devoted to criticism of the labors of other experimentalists will be equally disappointed. In

the position of an impartial student and observer, I have sought less to indicate defects than to exhibit accomplishments."

Of the work, fifty-three pages are devoted to a full description of all the types of dynamo machines, of which only ten describe the Sawyer. Thirty-three engravings fully illustrate this portion of the book. A view of each machine, with diagrams of internal construction in detail are given, and explained in the text with unusual clearness and perspicuity. Especially is this the case in the winding of the wires in the various methods of construction, so that any intelligent mechanic could, from the drawings and text, easily construct any of these machines. The various physical laws are introduced incidentally, as occasion requires. The writer has not seen any book from which so much detail can be learned as from this.

As the Sawyer light is of the incandescent class, of course the book treats of that class in particular, devoting sixty-one pages of text and thirty-two engravings to the lamps and carbons, nearly one-half of which is taken up with other patents. The details of the Edison alone are illustrated by seven diagrams, giving the best idea of the process of manufacturing the Edison lamp we have seen; also, a fine view of the Maxim form. As a part of the lamp, twenty pages and five plates are devoted to the manufacture and preservation of carbons. A page diagram is given of the Sprengel pump, as used by Edison and others. All conflicting patents appear to be given, with dates. The chemical notes beginning page 105 are excellent. His remarks, page 103, upon the comparative cost of arc and incandescent lighting present the subject so clear that we quote: "Light by incandescence is considerably more costly than light by the voltaic arc, when the volume of light obtainable is the sole consideration. The same expenditure of power that will produce a light of 1000 candles by the voltaic arc will not produce, on an average, more than half or one-third as much light as incandescence in a divided circuit. It should not, however, be forgotten that the power of any light decreases as the square of the distance from it, and that one-fourth of the light of the arc, distributed at four or five appropriate points, thus reducing the power of each light to of that of the voltatic arc, will give substantially as good a general illumination as the arc. The incandescent light is whatever may be desired. The arc light is necessarily a powerful one. The objection to it, if used without a shade, is its great intensity and ghastly effects; and in order to obviate these defects, glass shades of more or less opacity are employed, which, according to tests, in

volve a wastage in light of,

With ground glass......
With thin opal glass..
With thick opal glass..

30 per cent. 40 60

66

In some cases wastage is nearly 75 per cent." Experiments in France on the Jablochkoff, with the necessary opalescent globes. "it is found that only 43 per cent. of its full power is available." "It is proper to remark that

the light of the incandescent carbon is very un like that of the voltaic arc. Its characteristics are the characteristics of daylight; and this is true to such an extent that, from its soft and agreeable nature and absence of glaring effects, the degree of illumination afforded is not always readily appreciated." Besides, incandesscent lights do not require shades.

Chapter IX. treats of "the division of the current and light;" a most interesting chapter, because of the widely different opinions of physicists upon the subject. This should be read by all who are interested, as the author states his case and calculations clearly. If verified by future experiment they are of great value, but only actual experiment can decide. Chapter X is devoted to a description of the Sawyer regulator, called here the switch-a most important part of the system, as by it the light is almost instantly turned up or down, giving any degree of intensity of light as required by the person using it. The subject is illustrated in ten perspective and six diagram views, including the current regulator, one being a fine view of the Maxim governor. While these regulators admirably perform their func tions, he is careful, in perfect candor, to inform the reader (page 149) that, "By means of these regulators the changes in the circuit occasioned by the Sawyer switches for graduating the light are instantly balanced. But the fact remains that as much power is expended in driving the generator when there are a few as when there are many lamps in a circuit, and in a general distributing system, where economy is the prime consideration, such regula tors, however perfect in their operation, can have no practical application.' We venture to remark that this is not a peculiar defect of the electric light, but is a foundation principle governing every other industry.

Chapter XI is devoted to the consideration of the Sawyer patent for lighting the buildings in the blocks of a city by electric lights. The history, plaus, meters, switches, etc., requisite are fully set forth in the text and eleven diagrams. It also deserves careful study. In it the "Niagara Falls problem" is discussed at length, and, to our mind, settles that question.

The last chapter is devoted to the commercial aspects of the subject--that omnipotent question, Will it pay?" This chapter involves so many points, exhibits so many tables and calculations, which must be most carefully studied before an opinion can be given, that we have not time this month to devote to it. It is in print, in the book, for all interested to criticise.—Journal of Franklin Institute.

HOCK'S STEAM BOILERS.-In the issue of

MCK'S 1, 1881, The Engineer, of London, devotes nearly a column and a half to a review of the recent work on 66 Steam Boilers," by Engineer-in-Chief W. H. Shock. U. S. N. The reviewer calls it "the most important treatise on boiler engineering with which we are acquainted," and gives great praise to the illustrations, paper, printing, binding, etc. He says: "The plates are working drawings, which only require to be enlarged to be fit to send into the shops, and in the matter of constructive de

"

tails they show much that will be found novel and useful by English engineers.' It is not, however, clear to the mind of the American engineer why he should call the bracing of the rectangular boiler, shown on plate 18, a curious example" of "misplaced ingenuity." On this plate the best American practice of bracing rectangular boilers is illustrated, and the devices are in no way novel; but it is true that English practice, even in so-called first-class work, is, in many respects, very inferior to this. While summing up his opinion of the book in the last paragraph, the critic calls it "the most complete treatise on the marine boiler ever written," in which there is little to call for adverse criticism; and says further on, "it brings our knowledge of it (boiler engineering) down to the latest date and the questions which may be asked, and the answers to which cannot be found between the covers, must be few and far between," he makes the unreasonable complaint that it does not give a satisfactory answer to all the perplexing questions which now disturb the mind of the marine engineer. The critic finds fault with the writer for following closely in the footsteps of Rankine, in the chapters on combustion, transmission of heat and evaporation; but he does not point out a single fact which requires correction, nor does he indicate a safer guide. It is hardly fair in the critic to give it as his opinion that the investigation of the laws governing the draught of chimneys is simply inserted to give an air of erudition to the work." If he had studied this chapter carefully he would have found that a number of very important conclusions are drawn from this investigation. From the fact that the rules given in the book regarding the management of boilers do not differ essentially from English practice, the reviewer concludes that they are directly derived from it. This may be pardonable in an English critic. The reviewer desires fuller information regarding the use of steel for boilers. He should, however, be aware of the fact that many questions relating to this subject will necessarily remain unanswered for years to come. For the enlightenment of the critic, we add that steel boilers have been introduced into United States Naval vessels since the last three years and have given the most satisfactory results. This is due, no doubt, in a great measure, to the superior quality of the material employed, which is entirely free of the defects found in many English steels, that cause so much trouble to the English boilermaker. It will be seen that the few unfriendly criticisms, seasoning the high praise given to the book, are mostly trivial and unreasonable; the critic has been looking for new theories, but the author has given nothing but established facts, because the latter are more needed than the former.—Army and Navy Register.

and Cotopaxi to a distinguished audience. While purely athletic mountaineers had his sympathy in the practice of mountaineering as a sport, Mr. Whymper confessed that his sympathies were much more with those who employed their brains as well as their muscles. His journey to the Andes was to be one of work, and all its arrangements were devised so as to economize time to the uttermost. In observations for altitudes and position, in studying the manners and customs of the country, in photography and sketching, in the collection of objects of interest, from beetles on the summits of mountains to antiquities buried in the ground, he found quite sufficient to occupy his time. From Bodegas the party was composed of two Swiss mountaineers, the cousins Carrel, of Val Tournache, Mr. Perring, some muleteers, and their teams. When they reached the summit of Chimborazo, on the 3rd of January, after a most arduous climb, they found the wind blowing at the rate of 50 miles an hour, from the northeast, and driving the snow before it. With extreme difficulty, a reading of the mercurial barometer was effected. The mercury fell to 14.1 inches with a temperature of 21° Fahr. This being worked out, in comparison with a nearly simultaneous observation at Guayaquil, gave 20,545 feet for the height of Chimborazo. They began the descent at 20 minutes past 5, with scarcely an hour and a quarter of daylight, and reached their camp (about 17,400 feet above the sea level) about 9 P. M., having been out nearly sixteen hours, and on foot the whle time. Passing from an extinct to an active volcano, Mr. Wymper next gave an account of his journey to the crater of Cotopaxi. serving with the telescope, during an enforced stay at Machachi, that much less smoke or vapor was given off at night than by day, he resolved; if possible, to pass a night on the summit. On the 18th of February the party got to the edge of the crater, having passed almost the whole way from their camp at a height of 15,000 feet to the foot of the final cone over snow, and then over ash mixed with ice. The final cone was the steepest part of the ascent, and on their side presented an angle of 36 degrees. When they reached the crater vast quantities of smoke and vapor were boiling up, and they could only see portions of the opposite side at intervals, and the bottom not at all. Their tent was pitched 250 feet from the edge of the crater, and during a violent squall the india-rubber floor of the tent was found to be on the point of melting, a maximum thermometer showing a temperature of 110 degrees on one side of the tent and of but 50 degrees on the other; in the middle it was 75.5 degrees. Outside it was intensely cold, and a thermometer on the tent cord showed minimum of 13 degrees. At night they had a fine view of the crater, which has from a diameter north to south of 2000 ft., and from east to west of about 1500. ft. In the interior the walls descend to the bottom in a series of steps of precipice, and slope a good thousand feet, and at the bottom there was a nearly circular spot of glowing fire, 200 feet in diameter. On the sides of the interior, higher up

Ob