Percentage of rays of light reflected from glass roofs at various angles of divergence from the perpendicular (Bouguer)

1°.....................      2.5 per cent

10°.....................      2.5 per cent

20°.....................      2.5 per cent

30°.....................      2.7 per cent

40°.....................      3.4 per cent

50°.....................      5.7 per cent

60°.....................    11.2 per cent

70°.....................    22.2 per cent

80°.....................    41.2 per cent

85°.....................    54.3 per cent

Angle of roof for different heights and widths of house (Taft)

Height Feet

4 Ft.

5 Ft.

6 Ft.

7 Ft.

8 Ft.

9 Ft.

Width Feet

o /

o /

o /

o /

o /

o /

6

33 21

39 48

45

49 24

53 8

56 18

7

29 44

35 32

40 36

45

48 49

52 07

8

26 33

32

36 52

41 11

45

48 22

9

23 57

29 3

33 5

37 52

41 38

45

10

21 48

26 33

30 58

35

38 39

41 59

11

 

24 26

28 36

32 28

36 2

39 17

12

 

22 57

26 33

30 15

33 41

36 52

13

 

21 2

24 47

28 18

31 36

34 42

14

   

23 12

26 34

29 44

32 44

Among greenhouse builders, 32° is the pitch of roof that has practically been established for all houses up to 25 feet in width; beyond that width, 26° is commonly used for the slope or pitch of the roof.                                                                                       

Standard flower-pots.

American

The Society of American Florists has adopted a standard pot, in which all measurements are made inside, and which bears a rim or shoulder at the top. The breadth and depth of these pots are the same, so that they " nest " well.

English. — Chiswick Standards

 

DlAM. AT

Top

Depth

 

In.

In.

 

2

2

 

2 1/2

2 1/2

60's..................

3

3 1/2

54's..................

4

4

48's..................

4 /12

5

32's..................

6

6

24's..................

8 1/2

8

16's..................

9 1/2

9

12's

11 1/2

10

8's

12

11

6's..................

13

12

4's..................

15

13

2's..................

18

14

To prevent boilers from filling with sediment or scale.

(l) Exercise care to get clean water and that which contains little lime. (2) Blow it out often. It can be blown out a little every day, and occasionally it should be blown off entirely. (3) Put slippery-elm bark in the boiler tank. Or, if slippery-elm is not handy, use potato-peelings, flax-seed, oak-bark, spent tan, or coarse sawdust. (4) Put in, with the feed-water or otherwise, a small quantity of good molasses (not a chemical sirup), say one-half to one pint in a week, depending upon the size of boiler. This will remove and prevent incrustation without damage to the boiler. These vegetable substances prevent, in a measure, by mechanical means, the union of the particles of lime into incrustations.

To prepare paper and cloth for hotbed sash.

1.    Use a sash without bars, and stretch wires or strings across it to serve as a rest for the paper. Procure stout but thin manila wrapping-paper, and paste it firmly on the sash with fresh flour paste. Dry in a warm place, and then wipe the paper with a damp sponge to cause it to stretch evenly. Dry again, and then apply boiled linseed oil to both sides of the paper, and dry again in a warm place.

2.    Saturate cloth or tough, thin manila paper with pure, raw linseed oil.

3.    Dissolve 13/4 pounds white soap in one quart water; in another quart dissolve l1/2 ounces gum arabic and 5 ounces glue. Mix the two liquids, warm, and soak the paper, hanging it up to dry. Used mostly for paper.

4.    3 pints pale linseed oil; 1 ounce sugar of lead; 4 ounces white rosin. Grind and mix the sugar of lead in a little oil, then add the other materials and heat in an iron kettle. Apply hot with a brush. Used for muslin.

Paint for hot-water pipes.

Mix lampblack with boiled oil and turpentine. It is harmless to plants.