432 



SCIENCE. 



[Vol. XIV. No. 360 



Both the compressors shown here are duplex or double-acting, 

 but they differ in other features. One is actuated by steam direct, 

 and the other is intended to be driven by a belt. The valves and 

 much of the other mechanism of the compressors are constructed 

 on the same principles as those of the steam-pumps made by the 

 same company, which are too well known to require any descrip- 

 tion here. As the length of stroke of the pistons, in both the 

 pumps and the compressors, is about the same under all ordinary 

 variations of steam-pressure or load, much less clearance is needed 

 for the steam- valves than would otherwise be necessary, — an im- 

 portant point in the construction of compressors. Any desired air- 

 pressure may be maintained by means of an automatic regula- 

 tor, which opens or closes a valve in the steam-pipe. It may be 

 added that these machines are as compact and simple in construc- 

 tion as is compatible with the uses for which they are intended ; 

 and they are not liable to get out of order, even when run at high 

 speeds. 



GARBAGE CREiVfATION. 



We had occasion a year ago to describe the Engle furnace for 

 the cremation on a large scale of a city's garbage. To-day we are 

 able to show an illustration of a small furnace for the same use in 

 private houses. 



It is doubtless true that nature has its own way of transforming 

 offensive unsanitary matter into new forms in which it is no longer 

 dangerous ; but the application of fire can bring about in a few 



THE ENGLE FIRE-CLOSET. 



moments that which, if left to natural processes, would take weeks 

 or months to accomplish. 



The practice of cremation in place of burial is doubtless grow- 

 ing, and is each day gaining new adherents. A recent canvass of 

 the opinions of the leading physicians of Philadelphia brought out 

 the fact that the majority of them favored the fire method of dis- 

 posal of human bodies, several of them taking occasion to point 

 out that it all comes to the same thing in the end, the difference 

 being only in the time consumed. 



The Engle fire-closet is the application, on a somewhat smaller 

 scale, of e.xactly the same principles contained in the garbage 

 cremator described last year. By the use of two fires, one at 

 either end of a small furnace, the smoke and gas evolved in con- 

 sumption are destroyed, There is no escape of any offensive smell, 

 and the furnace perfectly supplies the use intended, for the sanitary 

 and economical destruction of all matters placed therein. 



The advantages of such an apparatus as this are obvious. It is 

 placed in a dwelling, where it is used for the reception and destruc- 

 tion of all garbage, as well as night-soil. It is especially useful in 

 places of public resort, hotels, and restaurants, where a large num- 



ber of people congregate, and supplies the place in such institutions 

 of an expensive and elaborate system and sewerage. It is in daily 

 use in large collegiate institutions and public-school buildings of 

 cities where no adequate system of drainage is in force, and is ser- 

 viceable for the destruction of the waste and worthless matters 

 produced by all manufacturing establishments. 



The Engle tire-closet is in use in hospitals, for the burning of in- 

 fected clothing, bedding, furniture, and other matter requiring to 

 be destroyed, from patients suffering with contagious or infectious 

 diseases. As an adjunct to the disinfecting and quarantine sta- 

 tions of cities and the general government, it is an auxiliary of im- 

 portance. 



The illustration shows the construction of an Engle fire-closet 

 adapted for the use of a single family. The matter to be destroyed, 

 both solid and liquid, is received directly through soil-pipes from 

 closets above into the evaporating pans and on the garbage bars 

 of the furnace. The flues into the chimney are kept open, and 

 there is no escape of any smell or odor into the surrounding room ; 

 and at the proper time fire is applied, and the contents are de- 

 stroyed. These fire-closets are constructed of steel, lined with fire 

 tiles, with receiving pans adapted for the purpose required, and 

 occupying a comparatively limited space. They are placed incon- 

 venient locations, usually in the lower part of the building, or in 

 the cellar, where access can be had to a flue or chimney of moderate 

 size. Being portable and easy to handle, they may be removed at 

 any time to any other desirable site as the exigencies of the weather 

 may require. 



A NEW PROCESS OF PROTECTING IRON EFFEC- 

 TUALLY AGAINST CORROSION. 



The following report on this process was made by Professor H. 

 Haupt to the Franklin Institute of Philadelphia sometime since: — 



" For a period of more than ten years experiments have been 

 made under the auspices of the Hydrogen Company of the United 

 States to discover a simple, economical, and practical method of 

 protecting iron and steel from all ordinary corrosive influences. A 

 large number of patents were secured, and about $100,000 ex- 

 pended in the erection of plants at Washington, D.C., Newburg 

 on the Hudson, and New York ; and some of the results were of 

 the most satisfactory character. Iron that had been treated bv 

 the processes referred to effectually resisted the action of nitro- 

 muriatic acid and other severe tests to which it was subjected, 

 while untreated iron was immediately attacked by the acids and 

 quickly destroyed. 



" But, although many of the specimens thus treated gave very 

 satisfactory results, others proved defective ; and it became ap- 

 parent to the contributors to the funds that the exact conditions as 

 regards temperature, quality, and quantity of material employed, 

 and duration of treatment, had not been so accurately determined 

 that results could be duplicated w-ith unerring certainty, — an 

 essential condition, without which no process could ever be made 

 a commercial success. 



" This explanation has been considered necessary to account for 

 the fact that an industry which promised results of such extraor- 

 dinary value to the public and to the parties financially interested 

 should have been allowed to linger until the greater portion of the 

 life of the original patents had expired. 



" But persistency has at last been rewarded with success. The 

 company succeeded in securing the services of a thoroughly prac- 

 tical and scientific engineer, chemist, and metallurgist. Dr. George 

 W. Gesner, who was enabled to discern the defects of former 

 treatments, and to remedy them successfully by new apparatus and 

 processes, which have recently been patented ; so that, while the 

 old patents are still held by the company, they have to a great ex- 

 tent been superseded by more recent issues, under which operations 

 now are and will hereafter be conducted. 



" The former treatment consisted in placing the articles to be 

 operated upon in a close chamber, similar to a gas-retort ; and 

 when heated to a temperature of about 1200° F., steam super- 

 heated in a separate furnace was introduced, followed by naphtha 

 or other hydrocarbon vapor. 



" The results, as previously stated, were not always uniform, and. 



