Compare and contrast Sonnet 39 from "Astrophil and Stella" with Sonnet 45 from "Delia".

Sir Philip Sidney was one of the earliest sonneteers, posthumous publication of his sonnets in 1591 predating Spenser's (1595), Daniel's (1592), and Shakespeare's (1609) sonnets). He used a variety of rhyme schemes, and Sonnet 39 is an example of this.

Sonnet 39, in iambic pentameter, has three quatrains and an ending couplet. The structure is what came to be called the Shakespearean, or English, sonnet form. The rhyme scheme is abab abab cdcd ee. Since the first and second quatrains repeat, it might be argued that the form is actually Petrarchan, with an octave abababab and a sestet cdcdee, though it differs from Petrarch's rhyme scheme abbaabba with variations in the sestet, excluding couplets, e.g., cdecde, etc.

There are two "turns" of thought, or voltas, within the subject of the sonnet. The first is line 5 where the thought turns from a supplication address to "sleep," which is personified through an apostrophe, "Come sleep, oh sleep," to the poetic speaker's initiation of his petition to sleep: "With shield of proof shield me from out ... / those fierce darts."  The second is line 9 where the speaker, Astrophil, offers up as sacrifice his "sweetest bed / ... / as being [sleep's] by right."

The resolution of the sonnet, which comes in the form of an explantion for the petition, is in the couplet:

Move not thy heavy Grace, thou shalt in me
Livelier than elsewhere Stella’s image see.

The couplet reveals that Astrophil is petitioning sleep's shield because he cannot relinquish Stella's image, thus intimating that Stella has relinquished him. Therefore, the subject of the sonnet is rejected love that Astrophil seeks to soothe with sleep. The implied metaphor driving the sonnet is the comparison of sleep to a deity to whom petitions and sacrifices may be made in return for kind blessings; Astrophil assumes that seeing Stella's image will be as meaningful to the god of sleep as it is to him:

thou shalt in me
Livelier than elsewhere Stella’s image see.

Similarly, Samuel Daniel's Sonnet XLV, in iambic pentameter, has three quatrains followed by an ending couplet in the Shakespearean form. The rhyme scheme is also what came to be know as a Shakespearean ababa cdcd efef gg. There are two voltas within the subject. As in Sidney's, the first is line 5 where the thought turns from "Care-charmer Sleep," a personification of sleep, to the "day" in which there is "time enough to mourn." The second is line 9 where the thought turns from day to "dreams, the images of day-desires."

The resolution to the problem occurs in the couplet where the poetic speaker extends his desire for sleep to include eternal sleep from which he never awakens:

Still let me sleep, embracing clouds in vain,
And never wake to feel the day's disdain.

The subject that has prompted the desire expressed in the couplet is that of scorned, or rejected, love: "Let waking eyes suffice to wail their scorn." This resolution is foreshadowed in lines 2 and 3 where Sleep is called the "Brother of Death":

Brother to Death, in silent darkness born,
Relieve my languish,

Sleep, death and dreams are all personified. The metaphor driving the sonnet is the comparison of sleep to death that opens the sonnet, "Brother to Death," and closes it in the couplet: "And never wake."