This is the season of the year when vacations are uppermost in our minds, and relaxation and out-door pleasures the order of the day. We know that many boats, built from descriptions published in these columns, are affording the builders much enjoyment, not alone from the pleasure of boating, but because the boats are the product of the owner's skill and workmanship. Descriptions of other boats are in preparation and will be published in due time. The first chapter descriptive of a thirty-foot auxilliary yawl will appear in the November issue, and as boats of this type and size are rapidly coming into favor, we are confident this description will be received with much interest.

While many readers may not actively engage in constructive work, the summer months afford an excellent opportunity for tours of investigation, and plans can be made for winter work. An -enlarged staff of contributors enables us to promise some decidedly interesting articles in new fields, and those "who like to make things " will find the forthcoming issues of the greatest service.

A number of recent inquiries from readers, requesting advice as to the most helpful books on technical subjects, prompts us to state that we shall be most pleased to recommend books for purchase by anyone making inquiry, provided stamp for reply be enclosed with inquiry. Having a large reference library at our command, information regarding technical books can be given from personal knowledge of the contents of the best books to obtain.

Many readers are familiar with some tool, instrument or device, a description of which would be of interest to other readers of the magazine. We shall be pleased to hear from anyone willing to supply us with such descriptions, for which suitable payment will be made. To avoid duplication of subjects already in hand, or in preparation, it is advisable that inquiry be first made as to the probability of an article being accepted before same has been written. We can then state whether a topic would be acceptable, and perhaps assist in making same more nearly in accord with our needs. Think over what you have made or done out of the ordinary, and write us regarding same.

We want photographs of articles described in this magazine which have been made by readers, and will give a year's subscription, or any one subscription premium, for each accepted photograph of this kind. A brief description of the article, mentioning any peculiarities of the work, should accompany the photograph.

Although Davy's lamp is the model miner's lamp, it has been the subject of numerous modifications. The best-known systems are divided into two classes, according to the principles on which based. In some the flame is surrounded by a thin metallic gauze. Should any quantity of explosive gas enter the lamp through this gauze an explosion will only take place inside the metallic gauze envelope and extinguish the light without outwardly communicating fire. In others the light is produced by an electric current inside a tube or small bulb filled with extremely rarified gas. The breakage of the bulb instantly causes the extinction of the light.