Our recent prize offer for articles from readers produced a large number of contributions, but the limited number of prizes prevented all but a few from being accepted. Another prize offer is therefore announced, -and this will be a regular standing monthly competition. It is especially designed to secure descriptions of tools and processes used in making machines and instruments, or in doing some special piece of work, likely to interest our readers. The amateur mechanic generally has but a limited tool equipment, and has many times to adapt or design a tool or instrument for the work in band. Information along these lines is of the greatest practical value to other workers similarly situated, and to obtain it we offer a prize of $5.00 for the best, a prize of $3.00 for the second best article, and $2.00 each for every other accepted article received each month.

These competitions close at the end of the last office day of each month; any article received will enter the competition of the month during which it is received. All articles for these competitions should be labeled "Handy Hints Prize Offer." If not so labeled, they will be considered as being submitted at regular space rates. Drawings should be made in India ink on smooth white paper, and manuscript should have liberal margins and not be too closely written. The prizes will be awarded as nearly as possible upon the following scale of marking:Importance or usefulness of the tool or instrument described, 50 per cent.

Literary value of the description. 30 per cent.

Excellence of the drawings, 20 per cent

It will be noted that half of the value is placed upon the thing described, this being to secure contributions from those who have information of value, but are not so situated that they can conveniently write the description or make the drawings. This plan furthermore provides that every one who sends an acceptable contribution will receive payment for the same, and the combined efforts of all our readers should be productive of much valuable information.

The third prize in our recent prize offer was awarded to Edmund P, Smith, Niagara Falls, N. Y., and James H. Hunter, Hartford, Conn., the prize being divided be-tween these two. Both contributions appear in this numoer. Other contributors in this competition will be advised regarding their articles as rapidly as possible.

The article "Attachments for Speed Lathe." by < Tobyansen, in the February issue of this magazine snould have been credited to "Carpentry and Building."

Enormous possibilities for power generation exist in the waste gasses discharged by blast furnaces, coke ovens and other metallurgical furnaces. Much greater progress has been made in utilizing these in Germany than in other countries. It is estimated that the so-called lean gases discharged from the blast furnaces of Germany are capable of developing 1,000,000 h. p. There are now built and under construction in Germany gas engines for this purpose aggregating 400, 000 h. p. These are mostly in large units, one firm alone having constructed 140 engines, totaling 120,000 h. p. The utilization of coke oven gases has proceeded more slowly, although the gas discharged from such ovens is of a much higher caloific value than the lean blast furnace gas. The richer the gas enables a greater power to be obtained from an engine of a given size than is possible with the poorer furnace gas, but the lean gas permits a higher degree of compression to be used without danger of premature ignition, this giving the somewhat paradoxical result that the poorer gas enables the higher thermal efficiency to be attained.

The defects noticeable in precious stones are (1) feathers: like rents or fissures in the inside; (2) clouds: gray, brown, or white spots resembling clouds; (3) sands: small bodies like seeds or grains of sand of white, brown, or red color; (4) dust: fine sand disseminated in very fine paticles in a stone.

Lead wool, made in Germany, is used principally for caulking pipes, the joint being filled cold against a backing of hemp or tarred yarn. It is considered a good substitute for melted lead in making joints for hub and spigot cast iron mains. The "blei-wolle" is-lead which has been shredded to about the size of heavy inroad, collected into bundles of convenient length and of a size in proportion to the joint to be filled, twisted -omewhat.