94 ANNUAL OF SCIENTIFIC DISCOVERY. 



stroke by hand or otherwise; or the beam may be turned, and the warp 

 threads delivered oft' and opened to form the shed by steam or other power 

 which may be employed to work the frame. Pins may be let in the fabric to 

 fix it in place, or it may be mounted on stakes with cross-pieces, or on swiv- 

 eled rods, or on adjustable frames, so that the position of the matting may 

 be varied when used for sheltering a plant; or it may be mounted in rollers 

 like a blind, to cover conservatories, etc. 



The breadth of the fabric varies from one foot three inches to two feet. 

 The lesser breadth is the better for protecting plants placed in rows or beds, 

 or in hot-houses and other like places, and the greater breadth for protecting 

 wall fruits, such as peaches, apricots, etc. The matting is made of any de- 

 sired length, being rolled up into rolls, like carpeting, as it leaves the loom 

 or apparatus in which it is woven, and which has been designed especially 

 for its manufacture. It weighs but little, and may consequently be trans- 

 ported with ease, and at a small expense. It may be handled roughly with- 

 out risk of injury, arranged in any desired form or manner, cut into any 

 required lengths, and, if desired, be reunited again without difficulty. It is 

 so easily applied in the garden or orchard, that ten men will, in a single day, 

 fix it over thirty thousand feet of plants, and that so firmly and surely that 

 it will resist the most violent storms to which it may be exposed. 



IMPROVEMENT IN PAPER -MAKING MACHINERY. 



An improvement, invented by Stephen Rossman, of Stuyvesant, New York, 

 has for its object the prevention of the breaking or tearing of the paper, as it 

 passes from the upper one of the second press-rolls to the dryer. This is 

 attained by the use of a small roll arranged parallel with the press-rolls, 

 between the highest part of the upper press-roll and doctor, about opposite 

 the line where the paper should leave the upper press-roll, on its way to the 

 dryer, so that the web of paper will pass between it and the upper press-roll. 

 The slight cohesion of the web to this small roll eases it off the upper press-roll, 

 and prevents its breaking; and if a slight break should occur in the web, it 

 prevents the edge of the break being carried under the doctor, and thereby 

 increased. 



MARSTON'S IMPROVED DOOR LOCK. 



A few years ago a talented burglar discovered that, by taking with a pin- 

 cer a firm hold of the end of a key, it could be made to turn, and that thus 

 the door of the sleeping apartments could be opened from the outside. This 

 knowledge having spread rapidly, and led to numerous practical applications, 

 some inventors set to work and devised a number of instruments, called burg- 

 lar alarms. In some of these a bell is made to ring; in others, powder to 

 explode, or a gas-burner is lighted, with a cracking noise, either by means 

 of electricity, or of a wound-up spring, acting by friction on a match. Mr. 

 Marston accomplishes the same result, by placing the inside key-hole of 

 locks out of line with the outside one. This arrangement renders it impos- 

 sible to turn tho key from the outside; but it leaves the outside key-hole 

 empty, and the lock might be picked through it. To obviato this, the lock 

 is provided with a sliding piece, which receives its motion from the key in 

 exactly the same manner as the bolt, and which moA r es over the outside key- 

 hole, and closes it hermetically, each time the door is locked from the inside. 

 The key is shaped so as to have no action on this slide when used from tho 

 outside. 



