Our readers are invited to contribute to this department, but no responsibility is assumed for the opinions expressed in these communications.

Letters for this department should be addressed to Editor of Amateur Work, 85 Water Street, Boston.

They should be plainly written on only one side of the paper, with a top margin of one inch and side margins of one-half inch.

The name and address of the writer must be given, but will not be used, if so requested.

Enclose stamps, if an answer is desired.

In referring to other letters, give the number of the letter referred to, and the date published.

Illustrate the subject when possible by a drawing or photograph with dimensions.

Readers who desire to purchase articles not advertised in our columns will be furnished the addresses of dealers or manufacturers, if stamp is enclosed with request.

(No. 3.) Brookline, Mass., Jan. 8, 1902.

To the Editor : Our residence is equipped with electric gas-lighting burners. These do not work well. Will you please advise me what I can do to get better service, and greatly oblige. Yours truly, J. P. H.

In this letter, as with many others we receive, there is an absence of particulars, making it difficult to give a satisfactory answer. Correspondents should send sufficient details, so that a proper answer can be given.

If the trouble with the burners is local, that is, some work and others do not, the sparking terminals may have become bent with use and simply need to be adjusted, so as to give a better spark, or a spark that will pass through the gas when turned on. If no spark can be obtained at a particular burner, the wiring is probably broken at some point along or near the fixture. If all the burners are faulty, and a feeble spark or no spark follows when turning on the gas, the battery probably needs renewing, or repairs of some kind. If a Lalcanche cell is used, examine the zincs. If much eaten away, replace with new ones. Also pour out the liquid, and fill each jar three-quarters full with water in which has been dissolved about a quarter pound of sal-ammoniac. If dry batteries are used, replace with new ones.

(No. 4.) Boston, Jan. 5, 1902.

What do astronomers think of Mr. Battell's discovery of the cause of the motions of the planets, published in the papers yesterday ? Ignoramus.

Ignoramus: - They do not think about it at all. The " discovery " is one of a very common class of announcements made by persons who, in making them, simply " give themselves away."

"Those things in it which are true are not new, and those that are new are not true."

Such statements are not entertained at all by astronomers.

The accepted explanation of the planetary motions accounts for all the observed facts, and enables these motions to be predicted with very great accuracy. No theory that does not fill these two requirements stands any chance of consideration, especially when, as in the present instance, it is not only unconfirmed by a single observed fact, but in its logical consequences is flatly contradicted by the evidence we have. Vega. (No. 5.) Waltham, Jan. 9, 1902.

I notice in the paper on drawing instruments, in your first issue, the statement that the hairspring attachment to the large dividers is not popular among professional draftsmen. Will the writer please explain ? Among all those I have met, it has been thought a very desirable feature, and its use only prevented by the additional cost, which, at the rates now paid to draftsmen, is practically prohibitive.

If I might make a suggestion as to another matter touched in the same paper, that of pencils, the best I have been able to find are Hardtmuth's " Koh-i-noor." These cost a little more than Faber's, but the difference is not worth consideration, in view of the excellence of the pencils. Draftsman.

Why the hairspring attachment is not more generally used on large dividers I do not know. The reason cited by the correspondent may be the correct one. I find it of great value in my own work, and think draftsmen, generally, would not be without it after once giving it a good trial. Earnest T. Childs.